Getting the 8506.421 error message. Have tried restarting several times. Used the Norton removal tool and the power eraser. Nothing works. When I reinstall (successfully) after I click on "Finish" the deadly "X Attention" window appears saying, again, that the same message problem has occurred and tells me to do the same thing all over again???????? Norton Chat help was worthless telling me to do the same thing(s) I just did. Huh?