OK which one is it? This one: DLL Hell Explorer often caches DLL files in memory for a period of time after they have finished being used. This can result in large amounts of memory being taken up by DLL files that are not even being used. To install this tweak: Go to Start > Run and type Regedit HKEY_LOCAL_MACHINE/SOFTWARE/Microsoft/Windows/CurrentVersion/Explorer Create a new sub-key called AlwaysUnloadDLL by right clicking in the left pane, then double click on the Registry key in the right pane and set it with a default value of 1. Reboot. To disable the tweak, delete the key. OR This one: Unload .dll's to Free Memory Windows Explorer caches DLLs (Dynamic-Link Libraries) in memory for a period of time after the application using them has been closed. This can be an inefficient use of memory. 1. Find the key [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer]. 2. Create a new DWORD sub-key named 'AlwaysUnloadDLL' and set the default value to equal '1' to disable Windows caching the DLL in memory. 3. Restart Windows for the change to take effect.