Disk Cleanup shuts my system down

[Rich]

When I run my disk cleanup utility it runs for a little
while and then all of a sudden it immediately and abruptly
shuts my system down. Any idea why this is occurring?
Could it be a virus residing in my system somewhere?

I have McAfee Anti-virus software and every time I run
their Disk Scan program the same thing happens.

Any feedback or insight anyone could provide would be
GREATLY appreciated.

Thanks,
Rich

 

[Bob I]

HAve you tried this in Safemode?