DO you have an image of what the error message is?

Is this a workstation machine? If it is, and it sounds like it is, you might want to go ahead and reformat it anyway. Also because it was preinstalled, you might want to just start over. Who knows what kind of files and so on are stored on the PC. Might as well get rid of them, install again, and start with fresh OS.

I recommend it to all friends whom buy used computers. I've bought one used PC for a family member and the first thing I did was format it, and start over. It just guarantees that you are starting from a new OS on a fresh format. That way you can set it up how you like, and you don't have to deal with the issues like you are having now.