Hi, I'm not sure if this is a Windows limitation or a Bug in AutoIt. If you run the following code on Windows 7 X64 you will get the message that rstrui.exe not exists in Windows\System32 but it exists if you execute rstrui from Windows start menu - run command it will run system restore. If you use the AutoIt Run command or shellexecute it does not If FileExists (@WindowsDir & "\system32\regsvr32.exe") Then Msgbox (64, "Regsvr32", "Exists") RunWait (@WindowsDir & "\system3