Hello, We have a Dell Latitude D630 (2GB RAM, 80GB HDD) with Windows 7 Enterprise installed and all Sleep/Hibernation settings disabled, yet the computer will go to sleep when left unattended overnight. Is there a setting (other than Power Options) or registry that I need to change to prevent this from happening?

Check the BIOS. The user's guide doesn't show all settings, so you have to look. There may be a setting to enable\disble support for sleep S3\S4. Is the BIOS the latest available? Have you created a custom power plan with "change advanced settings" sleep set to never?