A week ago, I bought ThinkPad W520 with Windows 7 Professional. When I click Start, right arrow button next to the Shut Down (could be other depends on your settings) and I realize Sleep is greyed out and when it is pressed, there is no response. What could be the problem?
This problem applies to all of the Windows-based systems.
Windows XP and prior Windows OS - Standby
Windows Vista, 7 and newer Windows OS - Sleep
1. ThinkVantage System Update
Go to Start, Control Panel, Lenovo - Update and drivers and install all the updates. You would need graphic card drivers to be installed in order for Sleep / Standby mode to work.
2. Manual Install (*applies to ThinkPad T#20,s/i/si and W520 with NVIDIA Optimus)
If the problem is not resolved after using ThinkVantage System Update, go to the link below, download and install this driver.