My computer is in the middle of booting up, then reboots itself?

I have a toshiba pentium 400mhz computer. I was playing a game and all the sudden, the computer crashed. When I rebooted it, a screen came up saying "Windows did not start normally" They give several options start windows normally, safe mode, etc... If I start it any way, it goes to boot up, a blue screen with data flashes for a millisecond and it does it a lot. Any ideas on whats going on?