When I carry out simple tasks in My Pictures such as moving or cropping jpg the PC frequently freezes. Logging off and logging on again clears the problem. When logging off explorer exe is shown as not reponding and I have to close it manually to continue. Having read around various posts it would seem that a repair reinstallation might be the answer. Before I do this does anyone else have a better idea and if not is this repair reinstallation the possible answer?

A Repair Installation should fix most flaws.

That being said we can try to troubleshoot before hand.

What is the full error message? Click the box for Details. What is the Faulting Module?


Also:

Look in your Event viewer: rt. click My Computer then click Manage then Event Viewer.
Or: Administrative Tools/Event Viewer or Start/Run/ eventvwr
Open the system as well as the application tabs & look for red X errors. Click error line for details.
Post back the source & event id & Description especially of errors that seem to coincide with this issue.
Also check the Information lines that might coincide with this issue.

How to view and manage event logs in Event Viewer in Windows XP

Be very sure to check for infectious material: virus/trojan/worm etc

I have come to know that the "explorer.exe" is afflicted by a virus that can cause this problem you are receiving.

The virus infects PE files, and searches for files with *.exe and *.scr extensions, on local drives, network drives and network shares on local network.

i.e. http://www.symantec.com/security_res...011708-2030-99
and
http://www.viruslist.com/en/viruses/...?virusid=20925
etc

Thanks Kazna3, have checked your link and run the full virus scan with System Restore switched off. Interesting point that from the link - I hadn't appreciated the need to switch off SR. However all clean, so not that.
Thanks also Jephree. I have checked with the event viewer as per your post. Even after causing a feeze the event viwer is not showing anything untoward. However I do notice that when I bring up Windows Task Manager in order to restart the frozen PC, System Idle Process shows a figure of 66 in the CPU column whilst everything else is at zero. Is that significant?

System Idle is the inverse of the CPU usage.

When System Idle is 99% the CPU usage is 1%.

If your System Idle is 66% then something is running the CPU up at 33% which would indicate a significant process is running.