In Windows 7, How to query times, when the computer was locked?

Is there a way to get a list of the following times:

• whenever windows is locked (using windows+l combo)


• 
  

  whenever windows is unlocked

  
  

  in the past week?

  
  

I've tried poking in the event log, to no avail.

Many thanks!

Answer

Event ID 4800 should correspond to The workstation was locked, and similarly Event ID 4801 should correspond to The workstation was unlocked.

If you don't see them in the Event Viewer, for recording future events try opening the Local Group Policy Editor (Start / Run / gpedit.msc), navigating to:

Computer Configuration / Windows Settings / Security Settings / Advanced Audit Policy Configuration / System Audit Policies - Local Group Policy Object / Logon/Logoff / Audit Other Logon/Logoff Events

and enabling the checkboxes for Success and Failure: