gregrocker: thanks for the link in Vista's forum-it is in great detail of this sleep problem. I tried the driver and Dell updates, but it did not make a difference. This is a sporadic (Windows) problem (as I have read the many complaints of others), that I was able to resolve previously. I checked the BIOS setting for power management as per the VISTA link: powercfg -a , and it showed that I only have S3 support, while S1 and S2 do not have the necessary firmware. The pc was not awoken by anything according to : powercfg -devicequery wake_armed. Is there a fix for this as I have set my power options to all different settings and it still will not sleep, but just shut off the screen?