Originally our terminal service server ran out of space, wondering why, we went to investigate and saw that ntuser.dat files were about 400MB or more. We also noted that new users logging in were taking 15-20 minutes to actually load into the terminal service the first time. What we eventually found out was that the HP Drivers were causing the issue.
You will want to delete this key + and sub keys (I advise running a export of the registry first, just in case):
– HKLM\Software\Microsoft\Windows NT\CurrentVersion\Terminal Server\Install\Software\hewlett-packard
Then we deleted all the user profiles that were bigger then 100mb and they recreated.
You will also want to verify that the default user registry hive (the ntuser.dat file) is not over 512kb or so (that was our default size).