[HKEY_LOCAL_MACHINE \ SOFTWARE \ Microsoft \ Windows \ CurrentVersion \ Explorer]
"AlwaysUnloadDLL"=dword:00000001
XP has a bad habit of keeping dynamic link libraries that are no longer in use resident in memory. Not only do the DLLs use up precious memory space, but they also tend to cause stability problems in some systems. To force XP to unload any DLLs in memory when the application that called them is no longer in memory, browse to HKEY_LOCAL_MACHINE \ SOFTWARE \ Microsoft \ Windows \ CurrentVersion \ Explorer and find the DWORD "AlwaysUnloadDLL". You may need to create this key. Set the value to 1 to force the operating system to unload DLLs.