Can I come out yet? Is it safe?
I have some software that I've been using for a while, and I want it to start automatically at boot-up. It does, now that I've turned off UAC. UAC wouldn't let it start. Now, if UAC had a "let this one run" as does (for example) Zone Alarm - then it would be useable. It isn't, so it's disabled. That's a choice I have to make. RealVNC and NHC both run as required.
I have a good firewall in my router, active virus protection, and several other protection utilities in the browser and other places. Like Simonta, I've had one virus in ten years, but that was a brand new one turned loose that very day and unknown to Mr McAfee (it was that long ago, that I was still using McAfee). I've had both laptop and desktop rendered unuseable by "features" in MS software several times rather more recently.
I had both machines offline for several days earlier in the year because I deleted a "Homegroup", not realising that Windows would lock down both machines as soon as I did so. I also had Windows Mobile Device Center (sic) wipe the contacts list off my phone with nary a warning. Each of those cost me around two days' work to recover. The virus took ten minutes to remove.
That's the risk you take, using computers. I check my two every month or so with Gibson's "Shields Up" and they both score 100% every time.