Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

About a month ago I reinstalled windows 7 (x64) on my laptop again. A couple weeks later, every so often when I wake my computer from sleep, the CPU starts working at 70%-95%. I tried waiting it out a couple times and the computer blue screens. It happens more frequently now (id say about every third or fourth time I wake it up). I've looked at the task manager and looked at all of the processes for all users (including system processes), but the sum of the cpu usage column (excluding idle) is like 10. Yet it says the total usage is really high and it takes >30 seconds for the mouse pointer to respond to my movements.

I am typically able to solve my own computer problems, but this one has me baffled because I don't even know what the culprit is. What can use the cpu, but not show up in task manager? Could it be related to something like bad graphics drivers or really hidden virus? My solution here is probably to just live with it until I get around to reinstalling the os again. I am hoping someone else can think of a better solution.

Update: I had the process explorer running every time I put my computer to sleep. This morning when I woke my computer, I noticed that it was happening again. It took me about 5 minutes to actually take the screen shot because of how slow the computer was, but I did get one. Hopefully someone can dissect this for me. enter image description here

share|improve this question
What make and model is the laptop? Often, a problem like this will be experienced by others with the same system and may have already been discussed (and hopefully fixed). – Synetech Feb 17 '12 at 3:38
I have a HP Compaq 8510w running Windows 7 (x64) – Bryan Watts Feb 17 '12 at 5:26
Aha! When I Googled “interrupts high cpu resume standby” yesterday, an HP thread was one of the top results. Throwing in you model helps (though not as much as I had hoped). Still… it looks like some HP systems have this issue. I’ve added links in my comment under my answer. – Synetech Feb 17 '12 at 16:46
up vote 3 down vote accepted

Check the kernel times (figure 1) in the Performance Tab. Is the red line high?

Task Manager is limited. Use Process Explorer to get a better insight into exactly what is spinning the CPU.

From your description, it sounds like one of the drivers is having a problem. Hopefully all that is required to fix it is to update the driver. Another fairly easy solution would be to adjust certain BIOS settings depending on what is causing the problem.

Figure 1: Kernel Times

enter image description here

share|improve this answer
Thanks, I'll try this next time it happens. Because I don't know how to recreate the problem at will, I'll have to wait until it happens again. – Bryan Watts Feb 15 '12 at 4:59
Set the kernel-times option (Task Manager remembers it). Then just before closing your laptop next time, run Task Manager and Process Explorer and minimize them to the tray (or even just leave them open). Then when you open the laptop, they should be there, displaying the results. – Synetech Feb 15 '12 at 5:09
I updated the question with some more information. If you think I should move this to a new question, let me know. – Bryan Watts Feb 16 '12 at 21:10
Forget Task Manager and System Explorer. Next time you want to stand by, open Process Explorer, right-click on the column-headers, select Choose Columns and check the Process Image->CPU History box. Then right-click the procexp.exe entry in the list and select Set Priority->Realtime (this way ProcExp will be able to show real-time information). Wait until the whole system idles (CPU usage drops to ~0%), then go into standby. When you resume, you can see the culprit because that process’ CPU graph will be obvious. (You can also click the CPU graph at the top and hover over the peaks.) – Synetech Feb 17 '12 at 0:09
I will do this next time it happens. Do you know why the 'Interrupts' cpu usage is so high in the image? It is never anywhere that high normally. – Bryan Watts Feb 17 '12 at 3:13

The first step in troubleshooting is to get the data. Here's some tools I suggest you:

1) MS TechNet Sysinternals Process Explorer to find which process takes so much CPU

There many setup possibilities with P.E. but I suggest you to try this column set:

  • Process (mandatory...)
  • PID
  • CPU
  • Priority
  • Command line
  • Start time
  • CPU Time
  • Network receives
  • Networks sends

2) From the same, dowmload and install Autoruns (to know what started with Windows) and Process Monitor (for future detailed system checkup like tracing boot process...)

Warning: use Autoruns with caution. Don't disable or delete anything unless you really know what's you're doing.

3) Download and install System Explorer for security checkup.

The processes signatures/checksums are compared to the System Explorer database, There's many useful features but one interesting is the possibility to send any file, program, to VirusTotal...

4) Check the Windows services

You may start the services.msc but the best is to run mmc.exe and add services.msc in a personalized "console". (This keep your display setup for the next time).

You may find useful information about Windows services at the BlackViper web site.

Hint: some Windows services slow down Personnal Computers when they are not connected. as a workstation, to a Windows Server such as Server, LanmanWorkStation and LanmanServer.

I suggest you to stop these services if they are running and put them in manual or disabled (IF your PC is NOT connected to a Windows Server...)

Another useful tool is NirSoft's ServiWin (for services and drivers...)

5) Check if there is defective driver for devices with devmgmt.msc (or add it in the same "console" created for services with mmc.exe...). Check if there's yellow triangle, if so update the driver... If not: don't fix what ain't broken...

6) Update Windows and your applications. I suggest you to double check with the online Secunia's Online Software Inspector and set the option Enable thorough system inspection (Java must be installed to run these tests)

7) Preventive Maintenance

  • Check the s.m.a.r.t. data of your Hard Disk (there's many free utilities for this: Piriform's defraggler or Speccy, SpeedFan with an online s.m.a.r.t. check up, etc.).

  • IF the s.m.a.r.t. is "good" run CHKDSK to detect and fix HD and FileSystem errors

  • Clean "TMPs" files with cleanmgr.exe (or a third party software BUT avoid Registry "cleanup")

  • Uninstall all unused softwares, UNutilities or "bugaboo" programs (alpha, beta, etc.)

  • Keep program loaded at startup to a minimum: in Autoruns check "Logon" tab...

  • Defragment the HD volumes

  • Check the PC temperatures (SpeedFan, Speccy, Open Hardware Monitor, etc) and remove dust in your PC if needed...

Last words:Make a System Restore before any modifications (just in case).

Hope this help you to find a solution. Let us know. :)

share|improve this answer
Thanks, I have everything setup for when it happens again. I'll let you know what I find out. – Bryan Watts Feb 15 '12 at 19:19
Ok. Give us feed-back. Have a nice day :) – climenole Feb 15 '12 at 19:40
I tried many of these tests and so far none of the tools have found any major problems and the problem still exists. – Bryan Watts Feb 16 '12 at 21:10
I updated the question with some more information. If you think I should move this to a new question, let me know. – Bryan Watts Feb 16 '12 at 21:11
That’s a bit of a generic, scorched-Earth, try-everything approach. A more narrowed approach specific to this issue based on the symptoms would be better. – Synetech Feb 17 '12 at 0:03

I also had the same problem - Windows 8.1 with i7 4700MQ- quad core -> one core - specifically always core 2 gets hot.

I found a workaround for the problem - after waking up from sleep - go to each windows explorer window that is open and press Ctrl+N -> this opens the same folder in a new window.

Do this for all your Windows Explorer windows that were open when you computer went to sleep.

After you have opened the new windows for all -> close the old windows -> Voila! your explorer CPU usage drops to negligible and CPU temp also comes down - don't know why it happens though!

Hope that helps!

share|improve this answer

I don't think much diagnostics is needed: Its a driver that does not support a certain sleep state.

Besides sleep, does this also happen when you hibernate? How about in safe mode?

I dont think its a process per say, I just think it is a driver that is having trouble, literally, waking up.

Update from HP and if fails, then (try) to go to the original vendor.

share|improve this answer

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .