Also it very well could be something as easy as the resolution. First try to boot a bootable cd/dvd/flash drive and see what happens, if it boots and the screen works, reboot and attempt to start in safe mode. As soon as the computer comes on start tapping the F8 key (7 or 8 times) and see if it gives you a screen with selection on how to start. Cursor up (or down) to the start in safe mode (without networking) and hit enter. When computer boots go to display settings and select 1024x768, apply and reboot.