Hi,
Random reboots are often a sign of over-heating. Things you can do:
1) Open the case and make sure all fans are operating, especially the cpu
fan. While you're in there, get a can of compressed air and blow out the
dust bunnies.
2) Make sure the drive tower is well ventilated and not stuck in some
department store computer desk pc cabinet with only a little vent hole in
the back.
3) Visit a local pc shop and have them add an intake or exhaust fan. This is
not something you should do on your own unless you are familiar with the air
circulation pattern inside your machine. Adding a fan can be
counterproductive if not done correctly.
--
Best of Luck,
Rick Rogers, aka "Nutcase" - Microsoft MVP
Associate Expert - WindowsXP Expert Zone
Windows help -
www.rickrogers.org