Author: tenbob
Subject: Unresponsive PC but CPU utilization OK
Posted: 04 December 2013 at 3:19am
Hi. Can anyone please suggest a testing strategy that might help me resolve this. I am having problems with my Vista PC that goes into an unresponsive state several times a day. Each incident may last several minutes during which the PC is unusable. The cursor moves normally, but whatever you click has no effect. Or there may eventually be a response after a delay of several minutes. Typically some windows go into a 'Not responding' state and the browser may report an unresponsive script. After waiting somewhere between 2 and 10 minutes the PC gradually returns to normal.
Subject: Unresponsive PC but CPU utilization OK
Posted: 04 December 2013 at 3:19am
Hi. Can anyone please suggest a testing strategy that might help me resolve this. I am having problems with my Vista PC that goes into an unresponsive state several times a day. Each incident may last several minutes during which the PC is unusable. The cursor moves normally, but whatever you click has no effect. Or there may eventually be a response after a delay of several minutes. Typically some windows go into a 'Not responding' state and the browser may report an unresponsive script. After waiting somewhere between 2 and 10 minutes the PC gradually returns to normal.
When it is unresponsive, the CPU utilization is fairly low. It's certainly not pinned at 100%. Nor is there any excessive disk or network activity.
At first I thought it might be a kernel mode program that was hogging the CPU. I ran Thread Profiling in Process Monitor, but I couldn't find any excessive kernel time in the relevant period. I also used a separate DPC Latency checker which indicated everything was OK. I have scanned for malware with various tools, but can't find anything. The swapfile shouldn't be an issue. I've left it for Windows to manage and I don't see or hear any thrashing at the relevant time.
I'm baffled as to what the PC is doing while it is unresponsive. It's not running my programs, but it doesn't seem to be doing much else either. The CPU utilization stays at a lowish level. What sort of situation could cause this effect? I don't really know what to look for. I'd be grateful for any suggestions as to how I could investigate further. Thanks, Bob
