Sounds like your video drivers are corrupt/missing.

Power up and have your finger sitting on top of the F-8 key. Immediately after the PC splash screen, start tapping the F-8 key. When you get a black and white DOS-like screen, arrow up or down to the "Last known good configuration" option and press Enter. It'll reboot.

If this does not fix the problem, open the CD tray and insert the CD. Power off and reboot.