Windows XP 100% CPU on startup

[vindaloo]

Hi,

I have a problem with Windows XP running on a laptop that has suddenly started occurring for no obvious reason (i.e. I've not installed or fiddled with anything recently). It was working fine one day and was shut down cleanly, and the next day it was started up and the following problem existed:

Windows starts up normally, but a little slower than normal. However the mouse pointer freezes and won't move at all. The keyboard still works (although the response is painfully slow) - I am able to use Ctrl+alt+delete to show the Task Manager. The CPU is constantly at or just below 100%, with the majority of the usage being taken up by System and System Idle Process.

I am able to boot up in Safe Mode, where the CPU is at 0% as expected and I can access everything that you would expect to be able to in Safe Mode.

I have tried the following with no success:

- Used MSCONFIG.EXE to specify a Diagnostic and Selective Startup.

- Used System Restore to restore to a previous checkpoint.

- Run a full scan with AVG but no problems were reported.

- Disabled all non-essential devices (Display adapters, Network Adapters, Sound, Video and Game Controllers etc.) in Device Manager.

- Rolled back the Display Adapter driver.

I'm at a bit of a loss now as to what to try next. It's an annoying problem because it takes so long each time to boot up normally, find out the problem hasn't gone away, and then boot up in Safe Mode to try something else!

My laptop (Acer Travelmate 4062) didn't come with a Windows XP disk, otherwise I'd try a Repair Installation.

Any suggestions would be appreciated. Fortunately I have another laptop that I can use to search for help otherwise I really would be stuffed!

Thanks,
Vindaloo

[BOAC]

See if a scan of some sorts is running, via MSConfig. Sounds like a bootup scan to me. Any AV/malware programme updates lately? Also worth running hijack this to see if it picks up any unexpected registry entries.

[Tarq57]

It seems you've looked at the "obvious" culprits, try disabling then uninstalling AVG. Quite a few folk have been having trouble with AVG8.
If no luck there, look at when the last MS update occurred. There was an out of band patch for IE7 recently, maybe that coincided with your problem.
You using SP3?

[vindaloo]

Update:

I uninstalled the last couple of things that I had installed recently (Webcam driver and Skype), although the laptop had been running fine for a couple of weeks since installation. This made no difference.

I then found that plugging a USB mouse in allowed me to move the mouse pointer about, so although the CPU was still running around 100% I was able to investigate without being in Safe Mode. The first thing I tried was updating the mousepad driver (and rebooting), but this made no difference to the CPU usage and the mousepad still didn't work.

However at the next reboot everything is miraculously back to normal! The CPU is now back to 0 or a low number, the mousepad is working and the keyboard is back to normal. My best guess is that the problem was related to the mousepad driver, but for some reason required more than 1 reboot to fix.

Another possibility was some sort of scan or virus running that has now finished, but I guess I'll never know. I'll run Hijackthis as advised by BOAC and see if it turns up anything.

Thanks for the replies,
Vindaloo

[Keef]

It's quite likely that the new mousepad driver didn't "take" until after a reboot.

[Guest 112233]

Give this site a go

The software has a good reputation.

I have no contact or role with the company.

Free ESET Online Antivirus Scanner (http://www.eset.com/onlinescan/)

they will want your E M address but the software is very through in the way it works. - I have used it in anger in similar circumstances.

CAT III

[vindaloo]

I spoke too soon! 1 reboot later and the CPU is back to 100% with the mouse pad not working :mad:. I've run the ESET antivirus but it hasn't found anything. Interestingly the antivirus was able to use as much CPU as it wanted, so whatever is hogging the CPU must be of a low priority. The keyboard still only works at about 1 keypress per second so this has taken ages to type!

Vindaloo

[vindaloo]

After lots more Googling, it seems that the laptop battery could be the cause of the problem. I pulled the battery out whilst the laptop was connected to the mains and the CPU usage immediately dropped to 0%. A reboot (without the battery) has restored the mousepad and keyboard to proper use, and everything is back to normal.

I'd installed a program called Process Explorer which showed the CPU usage in much more detail than Ctrl+alt+del - this showed the main usage was for Deferred Procedure Calls (see Wikipedia if interested) which led me on to Googling similar problems that were caused by batteries.

So it looks like my battery is knackered, almost certainly due to the fact that the laptop is always used at a desk on the mains, and is rarely run off the battery. Now that I think about it, the usable life of the battery has deterioated recently to the point that it says you need to switch to AC power almost as soon as it's has been unplugged.

Vindaloo

[ampclamp]

Hi Vin,
Used to have the same trouble with my Toshiba.Few years ago but sent it back for a bios update.Fixed it.
Have the occasional glitch (like all PC / windows machines) but nothing like the total lock ups that were happening pre bios update.

all the best.