Hi everyone. My Mac pro is playing up and I was wondering if anyone can give me some advice. Suddenly my mac is slowing down to a stop and windows are breaking up all over the screen. This is happening with either application windows and finder windows. Is this a know problem? Are there any quick fixes I could try before taking it to apple (and them charging me lots of money)? I used to have an iMac and could 'zap the pram' this often solved problems but I have no idea what I can do with my Mac pro. Also does tis sound lke a graphics card problem or a hard drive thing? Any help would be appreciated, Jonathan Update: Since posting 10 mins ago my mac pro has taken a turn for the worse. It powers up but hangs and I'm left with a blue screen with a few grey lines on it. Needs to go to apple I think. Anyone had any experience of this before?