Go into your BIOS and set the factory defaults. Then go back in and make sure Power Management is disabled in your BIOS. Then reboot saving settings, and press F8 until your given a few things to choose from. Here choose the Command Prompt only, and you should be able to type:
Hit enter, and then it will ask if your sure you want to do this... you will lose all data, blah blah blah, just tap the y key for yes and hit enter. When this finishes (shouldn't take long), it will reboot, you should now put your Operating System disk in. It should boot directly from it. If it doesn't, either move your CD-ROM to a number on the boot priorety before your hard drive, OR, reboot your machine and press F8 again, (with your disk in), and when the screen pops up, go to command prompt only agan. Now you will just have to type the following:
D: (or the letter assigned to your CD-ROM drive)
It should take over from here...