I've had that exact problem with my ASUS P5Q Deluxe board, and apparently there are some issues with the power saving settings in the BIOS...from what I can tell it's quite common on the P5Q series.
Had to restart, was prompted to reset the BIOS or enter setup by pressing F1 or F2.
When Windows started up it was "resuming Windows' rather than "Starting Windows"
Once on the desktop nothing loaded in my tray and drivers weren't working properly.
Restarted yet again and the internet wasn't working properly and the date was reset back to multiple years before.
Found a thread where a guy called up ASUS and they helped him with a couple BIOS settings:
Under Power Management:
Change Repost Video on S3 Resume from NO --> YES.
Change ASPI 2.0 SUpport from DISABLED --> ENABLED
Here is a link to the thread:
Sleep issues: Unable to wakeup - Cyber Tech Help Support Forums
Hope it helps!