Mr Tulip said:
If you're using MS products (I'm not suggesting you shouldn't), then their built-in antivirus is as good as anything you'd pay for. Running another product isn't harmful. It's just adding an additional load that has no real benefit.
Depends on the circumstances. I was the sole IT guy for a company that had 80+ folk. I ran a hardware firewall and a software firewall on them. Backed it up on a big cassette backup drive. Had two Windows servers and one Linux Red Hat. I would never put only the Windows antivirus on something like that. That was back in the days of Love Bug and I LOVE YOU viruses. I used McAfee with licenses if memory serves.
BTW - Red Hat was not my thing, but I put up with it. Will take Windows Server any old day, so much easier IMO
Then the last biz I worked at before I broke my back, we were installing VOIP. They wanted to do it themselves and I spoke with the boss and he said 'Let them' and gave me a couple of days off. After two days of being down, they still couldn't get it to work so I offered to come in on my second day off and help. I fixed it in about 5 minutes. Even though I had told them what not to assign, they assigned the same range of IPs as we were already using for our PCs... went outside the assigned range I was using, and low and behold, they worked!
Setup a couple of businesses for a friend of mine after that, but they were cloud based. All my knowledge of Servers felt like it just went down the drain!
"Life is what happens to you while you're busy making other plans." - John Lennon