How to enable Run As command

For Windows Vista, this Run As command is available in all versions. If you're not yet running Vista, you can still stick to XP. Yeah, this Run As is not enough to convince you to make a switch obviously.

To enable Run As in Windows XP or Windows 2000, you need to run related service.

For Windows XP,

• Go to Control Panel -->> Administrative Templates
• Double Click Services
• In the right panel, find Secondary Logon and double click.
• For startup type, choose Automatic and click Start.
• After that click OK.
  

Now secondary logon service is running. So that you can start using Run As command by right click on the program you want to run and choose Run As.

For Windows 2000, you do the same procedure, but look for the service named "RunAs".