I keep getting the above code, when I click on defender. the program is listed in the start program list, it shows in the control panel. but is not listed under "add or remove".I have googled this error and tried the suggested repairs, non have worked. MS will not allow a new down load because the program comes with vista. could any of you tech people suggest another route to fix this problem

which antivirus do u have on your machine ?

Cause AV usually Disable the defender , so there must be an UPDATE , or a program , asking for the proccess of the Defender !