Possible Duplicate:
Are there windows 7 keyboard shortcuts for Log Off and Standby?
How can I log off quickly using the keyboard in Windows 7?
Possible Duplicate:
Are there windows 7 keyboard shortcuts for Log Off and Standby?
How can I log off quickly using the keyboard in Windows 7?
Try this:
Win Key, RightArrow, RightArrow, L
Note that that means to tap the Windows-logo key, not to hold it while pressing the other keys.