Myth - "Enabling AlwaysUnloadDLL frees up more memory and improves performance."

Reality - "Adding this Registry Key in Windows 2000 or XP has no effect since this registry key is no longer supported in Microsoft Windows 2000 or later. The Shell automatically unloads a DLL when its usage count is zero, but only after the DLL has not been used for a period of time. This inactive period might be unacceptably long at times, especially when a Shell extension DLL is being debugged. For operating systems prior to Windows 2000, you can shorten the inactive period by adding this registry key."