Well done! I have three antivirus installed, and no complications. The trick is only one should be set as your active program, I suggest NOD32 for that, and stop AVG from running so it is only "on demand" as a second opinion. Since it is AVG I don't see why there should be a problem, it's pretty friendly with others. Just two points to remember: 1. AVG placed a boot sector scan line into your autoexec file (or your equivalent) so that needs commenting out, and 2. do remember to deactivate it as your email scanner. The other I'm leaving as I only just got a free license for LnS so am starting to learn it now, but I'm hoping it can replace ZA Pro which is pretty heavy on this old system.