How do I force Windows 7 to create a new domain profile with same name as an existing one?

  1. Rename the user's profile folder to Bob.old

  2. Logged in as an admin, go to Control Panel → User Accounts → Manage User Accounts. Domain accounts show there after an initial login.

  3. Delete the account for Bob

  4. Open regedit and make sure that the user is no longer in HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList. Delete it if present, even if it is followed by ".bak".

Then you can login as bob to recreate the local user profile, then copy your user data into it.

Source: Deleting a Local User Profile - Not as easy as one Might Assume