There is a reason they specifically recommend creating a new account. When a Windows server migration takes place, a problem can happen with the security identifier on the account. Each account has a SID and this is problematic when a server is switched out or migrated incorrectly. If NTUSER.dat is corrupt, there is very little you will be able to do to restore the account to operation. You can try deleting that file, along with NTUSER.ini, and NTUSER.dat.log. You can find these files in c:\users\your_username in other words from the command line:
%userprofile% when in the account
To see these files you'll need to uncheck "Hide protected operating system files" in Explorer under Folder Options - View.
You will want to delete these...