*checks his own power supply for a TUV thing, not knowing what hes looking for* Hehe, mine didn't come with my case though, but it wasn't really that expensive.
I would use the power supply, but not on a computer as powerful as most people build now.
One that came with a case I had once kept corrupting hard drives, and I didn't know it was that doing it until about the 3rd one, as they didnt go funny in a way to suggest the power supply, like it conking out. They just started acting funny and deleting stuff sometimes.