1. Find the key [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer].
2. Create a new 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.
I tried this after running a intense program, then watched the task manager; memory recovered it self.