Desktop won't Start Up

I have been having this issue for awhile now but now it is a problem. First issue is my power button. I have to push it just right for the PC to turn on. Must be a connection issue. When I finally get it to go on the PC keeps restarting. I also tried Safe mode and it will not get to that either. I have Windows XP Home. Do you think my hardware is going? Maybe it is something else.
All help is appreciated. I will reply with any questions yiou may have for me.

Luckily I have my Netbook to be sending this message out.

Sounds like the power button needs replacing. Anyway what I would do.

I took it into a local shop to have them check the power button. I am not sure about it restarting over and over without actually booting up.

It's possible that could be caused by the faulty power switch too. Or it could be power supply issues, but I would replace the switch first and see what happens.