Only one antivirus at a time. I'm not sure what the "Linked" term means but basically, antivirus programs "hook" the system files of a computer quite strongly.. When two such programs "fight" over an infected file, or even run at the same time in the background, there can be nothing but problems.
I happen to be a moderator on the McAfee forums and we see all sorts of issues when McAfee is installed with other antivirus programs.. In fact, IF you attempt to install McAfee after another AVP is on the computer, it will notify you of the problem and prevent the installation unless you remove the previous version. Some of the newer versions will attempt to automatically uninstall the other program. It's even pickier than that.. A newer version of McAfee won't install unless the older version of McAfee is removed as well.
Hope this helps.
Please clarify for me:: My belief was that you can have only 1 virus protection on your computer without cause conflicts. Meaning you should NOT run more than one on your computer at 1 time. Someone is telling me you can run more than one at a time if you "link" them. Example would be Mc Afee with AVG if they are linked.