Toshiba Tecra 510CDT keeps restarting and doesn't boot

[Techguy101]

Hey everybody! I know that my username is techguy101 but i'm only good at configuring OS's. Like the title says, I have a Toshiba Tecra 510CDT with Windows 2000 on it. I had just changed the power driver from Standard PC to ACPI I think. I restarted it and before the login screen turned up, it would restart without any warning. I've tried safemode startup and all the other choices, but none of them work. I've also read several other threads about this but they were for windows xp and most of the computers that were being talked about could boot a CD before startup or was shutdown using the power button which had caused the problem. I have a Windows 2000 bootable CD but there's no control that will let you boot before startup. Can anybody help with this problem?