In working with several networked environments, you frequently see a lot of weird errors that hit you from day to day. If you have seen the error “Group Policy Client Service Failed the logon” you know what I am talking about. If you have been looking for a resolution to this issue, I can tell you that in every case I have encountered this error it has to do with a profile problem. Either you have files in the profile that are corrupted or for whatever reason, permissions are not set correctly on critical files.
Especially if you are dealing with roaming profiles, things can tend to get corrupted from time to time. An easy way to get around this is to rename the profile of the user on the server to something like %username%.v2.bak or something similar. Logon the user and the profile folder will be created again automatically. You should see a successful login at this point. After you have logged the user into their new profile, you can simply map a drive or IPC into your profile server and their .bak directory which they should have permissions to and copy all the critical data over to their new profile. Logoff the user and the information is copied to the server into a healthy roaming profile. After you are sure you have everything the user needs you can then simply delete the .bak profile.