Fix For Today's AV Update Failure

For those who don't want to hear me talk... In brief, if you have a Dell, but no 3rd party AV suite, it's probably Dell Support Assist's scanner being treated as AV. Uninstalling that from Control Panel / Programs & Features solved the update failure immediately. If you have anything that scans (Duplicate file finder, system optimization, etc.), you may have to delete it if it's not an MS product.