Try to reinstall all your VC++ redistributable, and restart Windows, the Live Update should do that. And be sure, like check, double check and triple check, the antivirus is not blocking the Addon Manager folder.
As explained, so many times, you should never "disable" the antivirus, that won't work, even if it "looks" disabled, the antivirus windows service is still running, that's why we *never* said "disable the antivirus", but rather CONFIGURE IT to add the Addon Manager folder to the exclusions.