Loaded the software for a

Question

Loaded the software for a philips spc 500n webcam on my Dell and it's completely ballsed it up, I can't even log on now. I keep getting a message that that a Microsoft programme is trying to repair the problem but cannot do it and to contact my administrator. I've tried to restore the back-up before the installation but no joy and I've got things that I haven't backed up yet(I've only just bought the pc) so don't want to risk a complete rstoration. Any ideas before I give them a call.