Have you ever been using your computer and all of a sudden a blue screen will appear with white writing?
This screen is often refered to as the blue screen of death (BSOD).
A lot of people think that this means that there is something wrong with the computers hardware, but this is often not the case.
A lot of the time the "BSOD" will appear because some new software has not been installed correctly. This can be fixed by simply uninstalling and reinstalling the software (you could also try a system restore).
To ensure that there is not a program automaticly starting up and causing this error look at my "how to delete start up items" tutorial.