System locks up after period of inactivity.

[Guest]

After leaving my computer for a peroid of time ( about an hour or so ) the
system locks up. The keyboard and mouse buttons do not respond, I am able to
move the cursor but can not click on anything. The only way to use the
computer again is to shut it down and turn it back on again. I have made
numerous calls to Dell Tech Support, to no avail. They finally sent me a new
system and it does the same thing. I have tried various options in Power
Manangement, including having all shut-down options set on NEVER and
Hibernation disabled. With the old computer, if you can say three weeks is
old, I did re-install drivers, and XP, as suggested by Dell but nothing
worked. I am hoping there is some help out there for me.

 

[Mark L. Ferguson]

I would disable standby, and settle for using hibernation.

Disable ACPI in your BIOS settings, (if available) run setup again, and press F-7 at the 'Press F-6 for RAID' prompt. This will
disable ACPI and enable APM http://support.microsoft.com/support/kb/articles/Q216/2/51.ASP

..