Ok,
I've just bought the Guild 2 Renaissance and one of the reviews mentioned the legacy mod pack as an "essential"...
So I thought I may give that one a try, but after following the link to it from within another topic to the runeforge forum and from thereon to the steamcommunity page for it, I am somewhat flabbergasted: Is that page a 1st April leftover or what?
Install Instructions: Are they serious???? Especially as the following steps simply mentions to unzip the mod in the games directory overwriting files whence needed - and such a thing should maybe invoke some AV Steps - but wtf has the firewall to do with it. And why should I lower all my systems shields while beeing online and before downloading the patch (okok, they mention during installation... still wrong order of steps and still not a reason to disable the firewall, especially whilst gaming)...

So, is that patch trustworthy? Is my link the correct url for the patch, or is that all just a big hoax to teach some naive users a lesson???

You can try to install it without closing anti-virus. I installed it with anti-virus still on and it worked ok. It's just that anti-virus programs might look at the installation as mistrusted.

The problem with AV is that they sometimes only think they see a virus despite no virus being there. Depending on the files involved they might have had bad experience with it and hence advised to disable AV.

Firewall (at least not anymore) nothing to do with it. Can always stay on. Firewall would ONLY cause problems during download. Advice: never ever download those short little installers, always look for the full package.

I do remember times when you had to have 2 AVs on and each was saying: Virus detected, yep the definition files of the other AV.
Some AVs are even having trainer (no-cd-crack and similar) signatures in their definition file marked down as viruses. So giving quite a bit of false alarms. BUT unless the patch is from a fairly safe/trusted side you are always a bit on your own ;)

EDIT: Most of the time I have like 20 windows open and never had a problem. FF, 10 explorers, 2-3 for films, some text files, mp3 player......