Hi,
this may be the resolution settings problem.
when booting your computer, press F8 repeatedly to enter Safe Mode.
check the settings from there and then restart your computer.

I had this same problem with my pc and I found a solution. I was unable to find the Enable VGA mode when I pressed F8 which caused a little alarm to me. I had a windows xp cd with me fortunately, so I put it in the disk drive. When I pressed F8 at the menu screen it brought up a blue screen with four choices:

Select Boot Device:
Hard Drive
Removable Device
ATAPI CD ROM
Intel Core--- (bunch of numbers)

I chose run ATAPI CD Rom and then was asked to chose which mode to boot up in-Safe mode, Safe mode with networking, Safe mode with command prompt, Last known configuration, Start Windows Normally.

All three safe modes would get stuck on a line of code that read: system32\drivers\agp440.sys

So I tried it again after restarting and chose start windows normally and viola! It worked. I then shut down the computer and reloaded it to make sure and it runs normally now. I didn't try last known configuration so I don't know how that one responds. I don't know if it was an internal system error that caused this or if my graphics card is old (Its a GEForce so I don't think so.)