The server keeps on switching itself off

HI,

Please assist me. I have checked for a number of posibilities but the problem still prolongs. I am runing Windows server 2003. The machine always switches itself off. I have tried vaccuming the power supply because I thought it was over heating but that did not work. I looked for the Hard disk space and there is still enough space.

I do not know if anyone there has a solution to my problem. I would really appreciate it if I would get an assistance!

Thanks