I have a problem with my computer and I was wondering if anyone can please help me out on solving this problem thanks?

This is the problem below,

No it's just shutsdown the computer and then I can't turn it
on for a while I have to leave it for a few hours before i turn the
computer back on? Why does this happen how can I fix this?

I've just reformated my computer with windows xp media center 2005 with norton antivirus 2005..

Thanks for everyone's help