xp wont restart

i was recently given a little compaq celeron 1.3 i put in a couple oh hard drives installed xp but while xp was installing when it came to the part of the installation where it needs to reboot it turned off i restarted it with the start button on the front of the computer and the installion completed ,but some times when i push the start button it turns computer on for about 10 seconds then it turns off if i keep pushing the button iy eventually starts ,when the computer is running if i push the restart button in the start menu the computer shuts down instead of restarting ,any help or suggestions would be appreciated thanks rob

 

My first thought is a bad power supply, my second is blown capacitors on the motherboard. If you closely inspect the motherboard, look at all the capacitors very closely. They should be perfectly flat on top. If even one is just slightly 'popped' or bowed outward or appears to have crud stuck to the top of it, it's a bad capacitor. The crud is the electrolytic fluid inside the capacitor leaking out and can be off white to beige to brown to charcoal black in color. Sometimes it just looks like dust or lint, but if you blow on it, dust or lint would blow away.
Here's pictures of healthy, normal capacitors:
http://www.fotosearch.com/bthumb/GLW/GLW137/gwc118050.jpghttp://www.fotosearch.com/bthumb/uny/uny291/u12551922.jpg
The capacitors are the tall cylinders, not the copper coiled things.

 

ok thanks for your help i will have a look and see what i can see thank you rob