Problem: Unable to Log in to Domain on Windows 7, Vista, and Server 2008 with an Error message showing "The trust relationship between this workstation and the primary domain failed"
Solution: Log on as a local administrator. Right click Computer icon, select Properties. Scroll down to Computer Name, domain, and Workgroup settings and click Change Settings. Where it says to rename this computer, Click change. Enter any Workgroup name, hit OK leaving the domain. Repeat the process and then Join the domain again.
This time restart the computer.
Now you should be able to log in to the domain again.
