I have a Dell xps420 Vista PC with NVIDIA Geforce 8600 GTS video adapter with Dell Ultrasharp 2001FP LCD monitor. I am using DVI-D connection to monitor. When I run chkdsk or Spinrite the video goes out within 1 hour of starting either program. I have checked BIOS and find no power management that would make monitor sleep. I realize both chkdsk and Spinrite operate under DOS. I am wondering if that has anything to do with loss of video. Otherwise, the PC works just fine. Help? Ideas?I don't understand. You're running videos and checkdisk simultaneously? First of all, you cannot run checkdisk on the system partition from within the OS. Well, you can - but it doesn't do anything. You need to run chkdsk /r at boot (or from the Recovery Console if using XP) for it to repair problems it finds.

What is it you are TRYING to do?Hi Allan:
When you select chkdsk from Vista it runs at next system boot in DOS. Spinrite runs from its own cd and has a version of DOS on the cd it boots from. I do appreciate your help.Okay, I'm still not sure what you are trying to do. First, there's no DOS in Vista but that's another story. Why are you trying to check and repair the HD while watching a video? Utilities that run at disk level are both hd and cpu intensive and you really don't want to do anything else while they are running.I am not watching a video, just trying to monitor progress of chkdsk or Spinrite as it checks the drive. I started this as a routine check, but since I can't see it through to completion because of loss oss of video, I am getting concerned.
DavidSorry - I completely misunderstood. The SCREEN should not go blank when running checkdisk at boot - not sure what's causing that. Perhaps SOMEONE else has some idea. Sorry for the confusion.Thanks for trying. Dell won't help (WITHOUT charging mega $$)since PC is out of warranty and Geforce card is not original hardware, but upgraded by me. Nvidia won't support either. I might try switching back to vga cable.
David