always restarts
If you are using 2 sticks of 512 MB RAM, remove one and try it again. Repeat with the other stick of RAM. If this doesn't work, remove power and signal cables to your disc drives and remove all add-on boards and broadband/and/or modem, if you use it. Leave only the video card, one HDD (C:\ ) connected. Inotherwords, get down to the bare minimum to start the computer. good luck.