I just updated WGA Notification 1.5.0540 (19.6.2006). It updated its entry in Add/Remove prog and here in the reg: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\WgaNotify It also updated the wganotify.log in WINDOWS, wgalogon.dll and wgatray.exe in system32 in dllcache. It left behind the Download folder in Software Distribution. Inside there's an uninstall file. I'll investigate this further. It's getting late now. I'll rename those files offline, leaving only the reg entry and see.