My computer boots up but no display, I can see the bios and even Vista loading bar and if system stay idle a vista screen saver will play but when I press a button to "wake it up" there is nothing. I can hear that there is activity but nothig comes up on the screen. This is not hardware, I've changed Monitor, Video card, monitor cable, still the same. same symptoms in Safe Mode -it's got be be the Registry, can't just reload Vista cos I'm at SP2 and hence Repair says not possible. Windows Service Builder needs a circa 1.6Gb download and I'm unable to use my PC - Help please.