For those that are stuck at "Applying Settings" or if the machine is continously rebooting after a failed service pack installation:
(1) Boot into safe mode (without network support)
(2) Logon. If the UserInt.exe error message is received after logging in, hit CTRL+ALT+DEL, click Task Manager, click File, click New Task, and type Explorer.exe to load the shell or CMD to bring up a command prompt (see above posts for more details).
(3) Put the service pack CD in or cd to the directory where the service pack is located in the file system.
(4) Re run the service pack (always archive)
(5) After the service pack is done backing up files and installing the new files, it will try to update the IIS metadatabase and FAIL. You will receive a message box with an OK button. AT THIS POINT, PULL THE PLUG ON THE SERVER OR HOLD THE POWER BUTTON IN UNTIL IT TURNS OFF. DO NOT GIVE THE SERVICE PACK INSTALLER THE OPPORTUNITY TO ROLL BACK THE INSTALLATION.
(6) Turn the machine back on and boot normally. You will be able to log in properly at this point. If you right click my computer and click properties, you will note that the General Tab says you are running Service Pack 4. You aren't. Reinstall in the service pack (on the console this time!) and reboot. All is well.
The morale of this story is, NEVER apply a service pack or hotfix through a terminal service session. While it is unexcusable on Microsoft's behalf for the damage done to your server when it fails, it's best not to give them the chance to hose your server in the first place. Sooner or later, it will bite you.
