This method allows you to run processes as a different user.
I found this during the setup of virtual machine for Coded UI tests (it isn't part of the domain, and you need to have access to TFS via domain if you need to read data from Test Cases).
Using the code
On Windows 7, run PowerShell and enter:
runas /netonly /user:domain\username cmd
It will open command line windows running as a domain user.