A few months ago I ran into it and at the time, no removal tool worked. Sadly my dad didn't know how it crawled into the machine. Norton, McAfee seem to not stop this one.
Another member has an open discussion at link.
after McAfee quarantine the zeroaccess trojan, windows will not allow for the firewall to come on. Trying to set the setting I get the message "due to a unidentified problem, windows cannot display the settings. I also tried by going into the control panel. I send the information on zero access to McAfee for analyzing. Any suggestions?