Really sorry if this is a really daft question, but I have spent what feels like a small fortune on Sony dvds as I thought I could trust the name. I have a set of dvd+r and dvd+rw and I am on a Dell with XP. Basically none of the discs I am using are being accepted....I do everything to burn a copy and then the error message "medium not present" comes up! What do I do? Should I just throw all the dvds in the bin?!! And how do I avoid it happening again? Thanks in advance to anyone who can offer any direction!