My monitor will say "no video signal detected" mainly when switching users and logging off, but it will also do it randomly when I try to restart the monitor with the mouse/keyboard after the monitor shuts off for power conservation and sometimes when coming out of hibernation. The only way I can reinitialize the signal is to... 1. Blindly find shortcuts to reboot, sleep, login. 2. Switch to the other dvi port on the video card on the fly while the system is running (I know you're not supposed to do this.). When I had my old video card (Radeon x800-xl) installed it did the same thing. I thought upgrading the card to a more recent, perhaps more Vista compatible card may do the trick but the problem persists (HIS Radeon HD 4670 dual dvi). There are no secondary monitors or display adapters to disable in device manager. There is, however, two entries in Display Settings-Monitor tab: "1. Hanns.G HI221 D-sub on ATI Radeon HD 4670 2. (Default Monitor) on ATI Radeon HD 4670." I can't see a way to disable the second entry. I have updated to recent display adapter and catalyst control center. I have updated the bios from Gateway. Updated monitor driver. Will do Windows update if suggested but I have no faith that will solve the problem. The issue has been going on too long to do a system restore. My system: Gateway GM5643E (I know pre-made pc's are garbage) Intel Q6600 Vista 32bit upgraded PSU: 500W upgraded graphics card: HIS Radeon HD 4670 dual dvi added 2 hard drives analog/digital tv tuner 2x2gb corsair value ram onboard audio: Sigma Tel My system otherwise seems very stable. Any thoughts?