PC restarts automatically-why?

[MAliShah]

Hi all
My PC restarts automatically when i m doing my work. Sometime i work for hours but remains ok. sometime it restarts after one hour. sometime after four hours. sometime never restarts.
i have checked the power supply,RAM,Keyboard,mouse.
what may be the reason of automatic restart?
Please help.

Mashah

 

[bcastner]

Could you look in your Event logs and tell us what it says under System, and Application?

right-click My Computer, Manage, Event Viewer.

 

[wolluf]

which operating system? running same apps - or different ones? which apps do you typically run?

If its win9x/ME - try one RAM stick on its own if you have 2 or more (try each on its own).

has it always been like this - or did it start happening (if so, when & any hardware/software changes, major crash, virus etc)?