I am migrating 20 PC to Exchange online. All of the PCs run windows 7 x64, Office 2010 x32. All but one PC will connect to Exchange online. The one PC prompts for signon repeatedly.
After failing you can see that it did obtain the Exchange server it just could not logon.
The userid/password is correct and can connect through the portal.
Created a different user profile on same PC, and attempted to use outlook to connect using another exchange account that is working on another PC. This had the same problem.