I am running Win XP (SP3) on a machine with about 3.2 Ghz processor and 3.5 GB RAM. When I resume from standby, Task Manager shows about 40% CPU usage on the Performance tab. This doesn't map to the info on the Processor tab, which shows about 99% system idle process if I AM using other programs (like a web browser) and shows about 60% System Idle Process and 40% "System" process if I am NOT using any programs. In neither case is there a process or a set of processes that is using 40%. Services.exe and svchost.exe are listed at 0% usage. The number on the Performance tab may go up if I've done multiple resumes from standby without a restart in between; not sure about that because I haven't tested that recently.
If I do a shutdown and start up, or a restart, the Task Manager shows 0-1% CPU usage.
I have recently done exhaustive scans for malware and they were all clean. I have also recently reinstalled the OS onto a brand new hard drive, for unrelated reasons (hard drive hardware failure). However, I don't think the reinstall or the new hard drive is causing the problem because I had the exact same problem before I replaced the hard drive and reinstalled the OS.
I have a second PC with basically the same hardware and software, and it does not exhibit this high CPU usage statistic when resuming from standby. So maybe it's some device on the affected PC that's taking system resources when resuming. The main hardware difference between the two PCs is that the affected PC has a backup hard drive while the unaffected one does not.
- Is this high CPU usage statistic correct, i.e. providing info about what's really going on, given that it doesn't match up with what the Processes list shows? Can I investigate that further?
- If it is correct, what can I do to diagnose or fix the thing that may be causing the high CPU usage after resuming from standby?
Thanks for any ideas,