Log users off when roaming profile fails
Computer Configuration\Administrative Templates\System\Logon
Logs a user off automatically when the system cannot load the user's roaming user profile.
This policy is used when the system cannot find the roaming user profile or the profile contains errors which prevent it from loading correctly.
If you disable this policy or do not configure it, when the roaming profile fails, the system loads a local copy of the roaming user profile, if one is available. Otherwise, the system loads the default user profile (stored in Systemroot \Documents and Settings\Default User).