Hello again my Brazilian friend.
Not sure what you mean. Windows Defender, a I use it, is an application. You start it up and it scans for spyware. There is also a component that is installed with Windows Live Messenger that scans IM files, etc.
After I read your post I got curious and looked in the Control Panel to see if it was there as an unistallable application. It isn't.
If it can't be uninstalled, then I guess I have to rephrase my question. I CAN turn off regular scanning and just leave it there on the pc. That is, if it isn't doing anything useful.