Using the Windows+L keys together will lock your workstation running XP or Vista.

Did you realize that you can also disable this function by using a registry hack?

Manual Registry Hack

Open up regedit.exe through the start menu search box, and then browse down to the following key, creating it if it doesn't exist:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System

On the right-hand side, create a new DWORD 32-bit value named DisableLockWorkstation and give it one of these values:

• 1 - Disable Lock Workstation
• 0 - Enable Lock Workstation

The changes should be immediate, no need to restart anything.

Downloadable Registry Hack

Below is a link to a downloadable registry file. Just unzip and then click on the Enable or Disable script, depending on which action you feel like taking.

Download DisableLockWorkstation Registry Hack