AutoRestartShell controls whether the user shell, usually NT Explorer, will be restarted if it crashes. I have seen quite a few occasions where the shell crashes and this Windows NT / Windows 2000 registry hack allows you to just keep on trucking. When the shell crashes, the taskbar and desktop icons disappear. If you don't have AutoRestartShell set, you have to use keyboard shortcuts to logoff/logon if you know them, or simply power to PC off/on. Not necessary. Avoids losing work.

Hive: HKEY_CURRENT_USER
Key: Software\Microsoft\Windows NT\CurrentVersion\Winlogon
Name: AutoRestartShell
Type: REG_DWORD
Value: 0 user must log on/off to regenerate crashed user shell
Value: 1 user shell to automatically restart