Computer Restarting?

For about a week my computer has been restarting on its own. I doubt its overheating. I unpluged it from an exstention outlet and put it in the main out let. It improved the power time. I also went on control panel and put the power off to never. I also have SpySweeper with Anti-Virus protection on. I also defragment my computer and disk cleanup. I have 3 main programs. It keeps restarting after a couple of hours. Does anyone know the problem

Computer Restarting?symantic

This can be hard ware or software related. You need to have a basic checklist in mind.

Hardware:

If its hard ware then it could be that your Power Supply is getting ready to die. I also could be the memory, your motherboard, or lose cables.

Software:

A good virus program is good advice along with a good spyware program to defeat spyware on your system. Having a virus on your machine will make your PC do really funny things, including restart for no apparent reason. You may want to get the lastes updates on your virus software and try some free online scans. Use something different from the program you currently use. Not all virus software realizes all virus'. What you may scan one day to be clean if you use another virus program it will say its infected.

Take care of any posible software issues before you start taking your machine apart and trying to diagnose the problem in the hard ware.