freeze interview questions

Top freeze frequently asked interview questions

Why do damaged hard drives freeze the entire system?

Why does a hard drive which is known to have bad blocks (verified in HDTune and HDDScan), freezes down my entire system?

It is not the OS drive; it is attached to another SATA port, and I'm trying to copy files from it to another healthy drive.

I have experienced this issue with almost every damaged hard drive and every Windows PC.

I would expect to see freezing only for the program I'm using to copy the files (Windows Explorer, etc.), but instead my entire PC gets jerky, and I cannot browse web or watch movies while copying files from the damaged drive.

The long story.

I live in a rural area where there are problems with electricity (brownouts, etc.). I myself am using a UPS and my own hard drives are perfectly fine. But my neighbors often ask for help with their PC issues, and I often find that their hard drives are damaged, most probably because of electricity issues. Of course, after replacing the damaged drive I suggest my neighbors to buy an UPS.

I have always wondered, why my PC freezes entirely while retrieving data from damaged drives. Is it a hardware issue? Is it caused by the way OS reads data? Is it something Windows-specific, and I won't experience it on *nix?

Anyway, from now on I will use some dedicated software (such as Roadkil's Unstoppable Copier) instead of Windows Explorer, although I'm not sure if this will work differently, without freezing entire PC.

It is not a request for help, it is more for educational purposes, so I know why the things work that way.

Source: (StackOverflow)

How do I troubleshoot a Windows 7 freeze or slowness? [duplicate]

Possible Duplicate:
What are the first steps for diagnosing a slow machine?

I have a new pc with windows 7 which freezes randomly. I hit every single key on the keyboard and it works again. Is there a way to prevent windows 7 from freezing?

Source: (StackOverflow)


Hung process in Windows: Is there any way to see why?

I tried to print a doc in word, and word froze. Is there any way for me to see what resource it's waiting for?

I'm using windows XP and word 2007 (though I imagine the answer doesn't depend on the process that froze)

Source: (StackOverflow)

Can a process be frozen temporarily in linux?

I was wondering if there is a way to freeze any process for a certain amount of time?

What I mean is that: is it possible for one application (probably running as root) to pause the execution of another already running process (any process, both GUI and command line) and then resume it later? In other words I don't want certain processes to be scheduled by the linux scheduler for a certain amount of time.

Source: (StackOverflow)

My computer freezes irregularly

My computer started to freeze at irregular times for 3 weeks now.

Please note that this question change with each things that i try. (For additional details)

What happens

  • My computer freezes, the video stops. (No graphic glitches, it just stops)
  • Sounds stops too.
  • Sometimes, randomly, the screen on my G-15 keyboard flickers and I see characters not at the right places. Usually happens for about 1-2 seconds and a bit before my computer freezes.
  • I have to keep the power button pressed for 4 seconds to shut my computer down.
  • I still hear my hard drives and fans working.
  • Sometimes it works with no problems for a full day, some other times it just keeps freezing each time I restart my computer and I have to leave it for the rest of the day.
  • Sometimes my mouse freezes for a fraction of a second (Like 0.01 to 0.2 seconds) quite randomly, usually before it freezes.
  • No errors spotted by the "Action center" unlike when I had problems with my last video card on this system (Driver errors).
  • My G-15 LCD screen also freezes.
  • Sometimes my G-15 LCD screen flickers and characters gets carried around temporary under heavy load.
  • Now, most of the times, the BIOS hard disks boot order gets reversed for some reason and I have to put it to the right one and save each times I boot. (Might be unrelated, not sure, but it first started yesterday)

What I did so far

  • I have had similar problems in the past and I had changed my hard drive (It was faulty), so I tested my software RAID-0 array and it was faulty so I changed it. (I reinstalled Windows 7 with this part). I also tested with unplugging my secondary hard drive.
  • My CPU was running at about 100 degree Celsius, I removed the dust between the fans and the heat sink and it's now between 45-55.
  • I ran a CPU stress-test and it didn't froze during the tests (using Prime95 on all cores)
  • Ran a memory test (using memtest86+) for a single pass and there were no errors.
  • Ran a GPU stress test with ati-tools and furmark and it didn't froze during the tests. (No artefacts either)
  • I had troubles with my graphic card when I got it, but I think that it got fixed with a driver update.
  • I checked the voltages in my BIOS setup and they all seemed ok (±0.2 I think).
  • I have run on the computer without problems with Fedora 15 on an external hard drive (apart that it couldn't load Gnome 3 and was reverting to Gnome 2, didn't want to install drivers since I use it on multiple computers) I used it to back up my files from the raid array to my 1TB hard drive for the reinstallation of Windows. (So the crashes only happened on Windows) [The external hard drive is plugged directly on a SATA port]
  • I contacted EVGA (My graphic card vendor) and pointed them on this question, I'm looking for an answer.
  • Ran sensors on Fedora 15 and got this output: http://pastebin.com/0BHJnAvu
  • Ran 6 short different CPU stress test on Fedora 15 (Haven't found any complete stress testers for Linux) and it didn't crash.
  • Changed the thermal paste to some Artic Silver 5 for my CPU and stress tested the CPU, temperature was at 50 idle, then 64 highest and slowly went down to 62 during the test.
  • Ran some stress testing with a temporary graphic card and it went ok.
  • Ran furmark stress test with my original graphic card and it froze again. GPU had a temp of 74C, a CPU temp of 58C and a mobo temp of 40C or 45C (Dunno which one it is from SpeedFan).
  • Ran a furmark stress test and a CPU stress test at the same time, results: http://pastebin.com/2t6PLpdJ
  • I have been using my computer without stressing it for about 2 hours now and no crashes yet. I also have disabled the AMD Cool'n'quiet function on the BIOS for a more regular power to the CPU. When I ran Furmark without C'n'q my computer didn't freeze but I had a "Driver Kernel Error" that have recovered (And Furmark crashed) all that while running a CPU stress test. The computer eventually froze without me being at it, but this time my screen just went on sleep and I couldn't wake it.
  • Using the stability tester in nTune my computer froze again (In the same manner as before). I noticed that Speedfan gives me a -12V of -16.97V and a -5V of -8.78V.
  • I have swapped my G-15 with another basic USB keyboard (HP) and I have run furmark for about 10 minutes with a CPU stability test running each 60 seconds for 30 seconds and my computer haven't crashed yet.
  • Ran some more extended tests without my G-15 and it freeze like it usually do.
  • Removed the nForce Hard disk controller.
  • Disabled command queuing in the NVIDIA nForce SATA Controller for both port 0 and port 1 (Errors from the logs)
  • Used CPUID HwMonitor, here are the voltages: http://pastebin.com/dfM7p4jV
  • Changed some configurations in the motherboard BIOS: Disabled PEG Link Mode, Changed AI Tuning to Standard, Disabled the 1394 Controller, Disabled HD Audio, Disabled JMicron RAID controller and Disabled SATA Raid.
  • "A little hope", my computer frozen while watching a youtube video, but not from GPU and CPU 10 hours straight test.
  • I have put my BIOS back to defaults and: Disabled PEG Link Mode, Disabled HD Audio, Disabled JMicron RAID Controler, Disabled Serial Port Address, Disabled Parallel Port Address and Disabled Onboard 1394 Controller.
  • I changed the SATA cable for the 750GB hard drive and I also changed the slots at which they were plugged (1->2, 2->3, 3->4).
  • Changed the power saving feature of my graphic card from "Adaptive" to "Maximum performance".
  • Ran ECGA OC Scanner and got no freeze and no artifacts
  • I installed the Logitech drivers for my G-15 keyboard and my G-500 mouse and it restarted to freeze.
  • I removed the Logitech drivers for my G-15 keyboard and my G-500 mouse and it still freeze.
  • After changing everything except the hard drives, graphic card and power supply my computer is running very fine and I haven't run into any problems (This is with the exact same install of Windows that I had problems with my old motherboard). After removing my motherboard I have found some cambered capacitors (2) which might be the source of the problems. Since it almost clearly was a motherboard problem caused by these capacitors I am going to accept the answer that is the most related to this solution.

When it happens

  • When I play video games (Mostly)
  • When I play flash games (Second most)
  • When I'm looking at my desktop background (It rarely happens when I have a window open, but it does, sometimes)
  • When my Graphic card and my CPU are stressed.
  • Sometimes when my Graphic card is stressed.
  • Sometimes when my CPU is stressed.


  • Windows Seven x64 Home Premium
  • Motherboard: M2N-SLI Deluxe
  • Graphic card: EVGA GTX 570 (The non-oc one) [nVidia driver version 275.33 from EVGA's website]
  • CPU: AMD Phenom 9950 x2 @ 2.6GHz
  • Memory: Kingston 4x2GB Dual Channel (Pretty basic memory sticks)
  • Hard drives: Was 2x250GB (Western digital caviar) in raid-0 + 1TB (WD caviar black), I replaced the raid array with a 750GB (WD caviar black) [Yes I removed the array from the raid configurations]
  • 750W Power supply
  • No overclocking. Ever.
  • There have been some power-downs like 4-5 weeks ago, but the problem didn't start immediately after. (I wasn't home, so my computer got shut-down)
  • Event logs (Warnings, errors and critical errors) for the last 24 hours: http://pastebin.com/Bvvk31T7

I would like to thank everyone who have been participating, it's really nice to see that much people ready to help others. There was many great answers that might help other people with similar problems in the future (at least I hope so).

In this situation, how can I successfully pin-point the current hardware problem? (If it's a hardware problem)

Source: (StackOverflow)

How do I create a memory dump of my computer freeze or crash?

As a lot of us encounter freezes or crashes, I am wondering how do I manually initiate a computer to freeze in order to create a memory dump to view and diagnose any issues that may be involved with the crash?

I am looking on how to force the computer to crash instead of waiting for the computer to do it itself.

Source: (StackOverflow)

Perf samples too long, lowering kernel.perf_event_max_sample rate to

My machine freezes from time to time and I can get it back to working normally by pressing the space key.

I've been having this problem for two weeks now, but it was just once per day max. Now it's starting to be many per hour, until the point where the computer freezes and I'm not able to get it back.

I first thought it was the RAM, so I did a MemTest86+. The first try froze at 51 seconds. I decided to remove one of my 4 RAM and do the test again.

It ran for 40 minutes, did a full test suite without any problem. So I decided to boot my computer with the "default" RAM not plugged in.

The computer ran for 5 minutes and started freezing again.

I went to see the logs in dmesg and found a line containing:

Perf samples too long, lowering kernel.perf_event_max_sample rate to ...

Pressing escape worked, and I was able to work for a few minutes, and then another freeze, and a new line in dmesg (with the rate lowered from 25.000 to 13.000, then 7.000, 4.000 and 2.000).

At 2.000, the computer frozen one last time, and I had to force a reboot.

So it appears that either MemTest didn't find the problem or it's not related to my RAM.

Either way I don't know what to do or what to check (and with what tool). So far, I removed all the RAM except one (random) and I didn't had any freezes (which is good, I don't want to re-write this question ;)).

Here's my computers specs:

AMD Phenom(tm) II X6 1055T Processor 4 * 2048 RAM (GSkill DD3-1600 PC3 12800) One SSD for the OS Two RAID -1 for the data

I'm running Fedora 20 x64

Here's my uname -a :

Linux localhost.localdomain 3.14.4-200.fc20.x86_64 #1 SMP Tue May 13 13:51:08 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

Thank you for your help!

Note: The last time it froze, I was watching a Youtube video. But before that, it froze when I was working (coding).

Update 1 : I decided to remove all the RAM except one. The computer worked correctly for about 15 hours and then crashed. I was downloading a heavy file (380Mo) at the time. I'm starting to think it's related to disks.

Final Update : I finally located the problem to be the motherboard. I bought a new one and replaced it a month ago and since then, I didn't had any crash or odd behavior from my computer. I believe the issue is now fixed.

Source: (StackOverflow)

Solid State Drive Occasionally Freezes For A Minute While OS Is "Beach Balling"

Almost a month ago I bought Intel 330 128GB solid state drive, migrated my data with Intel branded limited-feature Acronis from old HDD to new SSD, optimized with Intel Toolbox and started using it. Occassionally I get close to 1 minute freezes while seeing operating system "beach balls" and animations still work, I can interact and click on something but nothing responds, nothing loads. Recently a couple of such freezes occurred in shorter amount of time in a row. I have noticed that if I stop interacting with laptop, the freeze lasts less time than if I was interacting with laptop.

But the bigger problem is when freeze just does not end and computer keeps being stuck unlil it is more than half hour and I run out of patience to keep waiting and feeling I need to restart the system because I am not getting anywhere. Such freeze happened while laptop was cold booting into Windows 7. This is when freeze hang occurred and I had to restart, only later to be greeted with Windows recovery screen stating something about faiure of boot sector and asking to insert Windows repair CD. But after I restarted, Windows booted successfully and all was well.

I have filmed video of freeze hang occurring in cold boot which you can see here (on video page look below for description):


As I have mentioned in the beginning, the SSD is less than a month old but here is S.M.A.R.T statistics just in case (TRIM is enabled btw according to CrystalDiskInfo):

enter image description here

enter image description here

I want to emphasize that this SSD is the only drive I have, yet it is working in RAID mode (it was enabled initially in BIOS by previous laptop's owner) on Intel Rapid Storage drivers. I am contemplating about switching to AHCI mode but want to be sure this won't cause data loss. Additionally, the stock firmware is the only firmware available currently, yet Intel does not respond to my posts in their community board.

If anyone here has this SSD model or generally has experience with SSD drives, I would love to know your thoughts.

Source: (StackOverflow)

How to diagnose repeated freezing of windows 7 (comes back alive in few seconds)

I installed Windows 7 in a 3 year old machine, it installed successfully, took all drivers and running great, but what happens is every 5-6 minutes it freezes for few seconds... 30 seconds to 1 minute and then comes back alive.

I checked Event Viewer, nothing matching the frozen timeline.

I would appriciate any help on how to detect causing service/hardware.

After it comes alive, everything runs normal, I did run task manager and checked cpu usage, at time it freezes just before and after that no task took more cpu or memory, it was like idle machine.

No external usb drives or no devices, on board intel desktop board with SATA HDD, SATA hdd running in absolute good mode.

Source: (StackOverflow)

Why does Windows 7 mouse freeze after resuming from sleep?

A similar question previously posted at Super User is Why Does My Windows 7 PC Freeze After Waking from Sleep?, but none of the previous answers intially appeared to solve my problem or were the same as my initial answer.

On one of my Windows 7 machines, the mouse would be permanently frozen after the machine woke up from sleep. The mouse would not move though the cursor was displayed. I had no option but to power down the machine and reboot.

This happened often, though not always. If the machine had only been sleeping a few minutes, I could wake it up and use the mouse. If the machine had been sleeping an hour or so, then the mouse would be permanently frozen when the machine woke up.

Source: (StackOverflow)

Why does my Windows 7 PC / SSD drive keep freezing?

I have a ~1 yr old PC with a primary SSD hard drive. I notice quite often that the PC will freeze for 30secs to several minutes, displaying the "Spinning blue wheel" mouse icon during this period. It then releases and returns to normal.

When I look at the Resource Monitor during this period, I notice that the disk activity is always at "100% Highest Active Time" solidly for this period. But the actual amount of disk activity doesn't look that high to me (<1Mb per second). Memory and CPU are never remotely stressed.

Usually the anti-virus software (Kaspersky anti-virus is the most active user of disk activity, but that doesn't seem so unusual to me. I'm typically not stressing my PC too much during these periods, just a bit of light web surfing etc.

My guess is that it is a problem with the drive, but I'm not sure what to do next (other than buy a new one).

Any ideas?


Source: (StackOverflow)

What do do when Linux gui freezes

I'm running Gnome with compiz in Ubuntu 10.04. Sometimes the gui will freeze. I can move the mouse, but I can't interact with programs. The only thing I can do is go to a terminal window with Alt+Ctrl+F(n). From there I login and do a sudo reboot. What else can I do at the terminal instead of rebooting to deal with this problem when it comes up?

Source: (StackOverflow)

How do I troubleshoot hardware issues related to a computer freeze/crash?

What are some common guidelines and issues related to hardware being the issue of a computer crash?

What should I look for and how do I troubleshoot these problems?

What are some tools that are useful in diagnosing these hardware related crashes?

I am looking to be able to isolate the problematic device with specific tools and guidelines. For example if device X is causing system failure how do I go about diagnosing it?

Source: (StackOverflow)

Windows 7 is stuck at "Starting Windows" when I attempt to boot computer

Basically, whenever I turn on my computer, it gets to the Starting Windows phase and just stays there. The startup animation still plays, yet it gets nowhere.

  • I have tried booting into safe mode, however it gets stuck at loading CLASSPNP.SYS. It then freezes there and doesn't continue booting.

  • I have tried booting into recovery mode from the hard drive, and it freezes after displaying the background image. I have tried booting from a recovery CD, which works, and I was able to use system restore. However, using system restore did not fix it, and it still is stuck at the Starting Windows screen.

  • I have tried booting a Windows CD (Windows 8 Retail Installer) to see if I could upgrade it to fix this issue, however that froze at a blank screen after it got past the boot logo.

  • I have tried changing around the BIOS settings (including resetting), to no avail.

  • I have tried re-plugging the internal PSU cables (this is a custom-built desktop), yet this has changed nothing.

  • I can boot into a loopback Ubuntu install on the same drive, which works fine, other than the fact that it has issues with some of the USB ports and the network card.

  • This system has worked fine for the past few months, completely stable, and nothing in the configuration has changed before this error started happening.

  • Startup Repair on the Windows recovery CD doesn't find any issues.

  • Unplugging my secondary hard drive or swapping around memory doesn't change anything.

  • The hard drive itself is fine, it hasn't shown any signs of failure and once again, boots my other OS fine.

If anyone could help with this, that would be great. I can't seem to find any possible solution to this.

If it makes any difference, my system specs are as follows:

  • AMD FX-8320
  • Gigabyte GA-970A-D3
  • 4GB of DDR3
  • Radeon HD 6870
  • 550w PSU

I'd like to not have to reinstall Windows, for I have more than a terabyte of data that I would have to back up if that becomes the only option.

EDIT: I have since tried the following:

  • Tried the solution involving restoring files from RegBackup, which changed nothing.

  • Tried testing everything with Hiren's boot CD, everything comes back as fine.

  • Tried disabling everything unnecessary in the BIOS and unplugging everything unneeded, it still hangs.

  • Tried swapping out every possible combination of RAM, it still has the same result. The RAM is not at fault it seems

  • Tried every GPU I own (which is many!) and it still hangs at the exact same place.

  • Tried minimizing the power consumption as much as possible, even using an old PCI graphics card. It still hangs at the same place in the same way, signifying that it's not the PSU at fault.

  • Tried resetting the BIOS again, still nothing.

  • Tried every possible combination of BIOS options, even downclocking everything, it still hangs in the same spot.

  • Tried upgrading the BIOS from version FB to FD, which changed nothing.

Based on this, I would conclude the motherboard to be at fault. Are there any other possibilities? I don't want to spend $150 for a new motherboard.

EDIT 2: This is what it gets stuck at when I try to boot into safe mode:

enter image description here

Note the slight graphical corruption at the top of the screen. No matter how I set up the system, this seems to be there. In addition, either it has stopped booting into safe mode now, or it takes upwards of 2+ hours, and I haven't left it running for that long.

Source: (StackOverflow)

How to diagnose computer lockups and freezes?

I built a desktop computer a couple years back with the following specs:

  • CPU: Intel Core 2 Quad Q9300 Yorkfield 2.5GHz 6 MB L2 Cache LGA 775 95W Quad-Core Processor BX80580Q9300
  • Motherboard: EVGA 122-CK-NF68-T1 LGA 775 NVIDIA nForce 680i SLI ATX Intel Motherboard
  • Video Card: Two EVGA 256-P2-N758-TR GeForce 8600GT SCC 256 MB 128-bit GDDR3 PCI Express x16 SLI Supported Video Card
  • PSU: SeaSonic S12 Energy Plus SS-550HT 550W ATX12V V2.3 / EPS12V V2.91 SLI Certified CrossFire Ready 80 PLUS Certified Active PFC Power Supply
  • Memory: Two G.SKILL 4 GB (2 x 2 GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory Model F2-6400CL5D-4GBPQ

Since its inception, the machine has periodically locked up, the regularity having varied over the years from once a day to once a month. Typically, lockups happen once every few days.

By "lockup" I mean my computer just freezes. The screen locks up, I can't move the mouse. Hitting keys on my keyboard that normally turn LEDs on or off on the keyboard (such as Caps Lock) no longer turn the LEDs on or off. If there was music playing at the time of the lockup, noise keeps coming out of the speakers, but it's just the current frequency/note that plays indefinitely. There is no BSOD.

When such a lockup occurs I have to do a hard reboot by either turning off the computer or hitting the reset button.

I have the most recent version of the NVIDIA hardware drivers, and update them semi-regularly, but that hasn't seemed to help. I am currently using Windows 7 x64, but was previously using Windows Server 2003 x64 and having the same lockup issues.

My guess is that it's somehow video driver or motherboard related, but I don't know how to go about diagnosing this problem to narrow down which of the two is the culprit.

Additional information re: cooling Regarding cooling... I've not installed any after-market cooling systems aside from two regular fans I scavenged from an older computer. The fan atop the CPU is the one that shipped with it. One of the two scavenged fans I added it located at the bottom tower of the corner, in an attempt to create some airflow from front to back. The second fan is pointed directly at the two video cards.

SpeedFan installation and readings Per studiohack's suggestion, I installed SpeedFan, which provided the following temperature readings:

  • GPU: 63C
  • GPU: 65C
  • System: 76C
  • CPU: 64C
  • AUX: 36C
  • Core 0: 78C
  • Core 1: 76C
  • Core 2: 79C
  • Core 3: 79C

Update #3: Another Lockup :-( Well, I had another lockup last night. :-( SpeedFan reported the CPU temp at 38 C when it happened, and there was no spike in temperature leading up to the freeze.

One thing I notice is that the freeze seems more likely to happen if I am watching a video. In fact, of the last 5 freezes over the past month, 4 of them have been while watching a video on Flickr. Not necessarily the same video, but a video nevertheless. I don't know if this is just coincidence or if it means anything. (As an aside, each night before bedtime my 2 year old daughter sits on my lap and watches some home videos on Flickr and, in the last month, has learned the phrase, "Uh oh, computer broke.")

Update #4: MemTest86 and 3DMark06 Test Results:

Per suggestions in the comments, I ran the MemTest86 overnight and it cycled through the 8 GB of memory 5 times without error. I also ran the 3DMark06 test without a problem (see my scores at http://3dmark.com/3dm06/15163549).

So... what now? :-)

Any further suggestions on what to check? Is there some way to get a stack trace or something when the computer locks like that?


I have never did figure out the particular problems, but based on the suggestions here and elsewhere, I'm presuming it was a motherboard issue. In any event, I recently upgraded my system, buying a new motherbeard, PSU, CPU, and RAM, and that new rig has been working splendidly the past several weeks. I am using the same graphic cards as in the old setup, so I think it's safe to reason that they weren't the cause of the problem.

Source: (StackOverflow)