Correct, I've been working on a UDF but been caught up with other project work, so haven't really been able to do a complete test: #RequireAdmin ;~ Required when writing to System Environment Variable #include <Array.au3> ; #VARIABLES# =================================================================================================================== Global $MAX_VALUE_NAME = 1024 Global $HWND_BROADCAST = 0xffff Global $WM_SETTINGCHANGE = 0x001A Global