Black screen, system error

Hello,
I have serious problem. I have windows xp. Tried to upload extra brushes abr file in photoshop cs5.
In next moment the screen went blue with system error message that said it detected error and shut windows down. I tried to restart, but the Start button didn't reacted. Had to unplug the cable from power.
I put it back in and pressed Start to turn computer on, but instead of showing bios, it shows black screen. Start button still doesn't react to shut it down or restart. If I could get first screen with bios, I could try to enter safe mode and simply delete the file which caused trouble. But now I can't do anything. I really need help here, because PC is essential in my work. Help!!!