[pompous, uncalled for rant, please ensure that you skip the following :-) ]
I would never use any of these anti virus products. Operating system designers and web browser designers have not tested them as part of the the testing process and the designer of the antivirus will not necessarily have enough knowledge to avoid messing up the operation of the o/s. Also o/s designers may not have allowed for what the antivirus software gets up to. In my opinion, which is not so humble, it is asking for trouble as there is no guarantee that the system will continue to work reliably.
A second point is the false sense of security. The great majority of damaged systems I have seen have antivirus installed. It just didn't work in the slightest. Their definition of malicious was also two narrow. Users have lost their internet connection or their email because they inserted an evil cd or downloaded something evil and were then left not knowing where to turn. (Their settings were reconfigured without their consent.) My next door neighbours system was damaged by something they accessed on the web when it was roughly one month old and anti virus had failed.
Just do two things. Never login as an administrator, or as root, and configure the operating system properly so that malicious code can not be downloaded and run at all, which can be done if you have the right expertise, and if not then someone with the right expertise should be consulted. Another alternative is to run eg a web browser inside a VM instead.
I would not recommend removing antivirus in case the system becomes unusable as a result. If you want to get out of the situation, it means backing up thoroughly and doing a wipe+clean o/s installation, not an upgrade-in-place installation. The best way to do that is to get a new fresh higher performance hard disk and simply keep your old disk as a full backup. Are over he old disk, install the new disk, then install a new fresh retail o/s on the new disk without any unnecessary bloat or crud and configure it securely or get help in doing so, and copy your stuff from the old disk. Never buy ‘Home’ editions of MS Windows as in them various essential security features are disabled and so they cannot be configured securely, which I think is totally unforgivable. Security is required by all users, not just by employees.