Windows Vista
Downloaded Heroes of Might and Magic 2: Gold
The setup file is definitely 100% done
I click on it, the mouse changes to the timer thingy briefly and then nothing

Tried redownloading twice
Tried rebooting computer

Seriously, move to Win 7, or downgrade to XP. Anything but Vista. Have you tried (and I don't remember the option) running as administrator, as I remember Vista having nightmare priviledges. I note on 8.1 it can take a long time, or not at all to run exe's.

Sounds like your AV might be getting in the way. Try disabling it while running the install.

Have you tried redownloading the setup file through the GOG website? Sometimes they can get corrupted.

After you've double clicked on the Setup file, have you tried opening the Task Manager and looked to see if the game or GOG setup or any variation of that shows up anywhere (it might take a moment or two)?

Some games can hang and take a long time to get the actual installer to pop up.

How long did you wait? With some installers where the setup.exe is very big, there's sometimes quite a pause before anything seems to happen after double-clicking the setup.

My theory is that virus scanner or some "Microsoft Gaming Service" or whatever is scanning that big exe file before proceeding, and that may take time. I guess that's why GOG seems to have moved to the model with many games that the setup.exe is quite small (a couple dozen megabytes), and the bulk of the data is on those bigger setup.bin files. Then it doesn't take that long because the .exe is fairly small.

In the case of HOMM 2, the exe apparently is 356 MB, so... might still be the issue.

Just to make sure the setup file is really ok:

Right click on setup_homm2_gold_2.1.0.29.exe.
Select "Properties".
Select the "Digital Signatures"-tab.
Click on the signature on the list ("GOG Limited...").
Click on "Details"
Wait (the bigger the exe file, the longer you'll have to wait; in this case it shouldn't take that many seconds)
It should say "This digital signature is OK.", meaning the file is ok.

I installed this on a Vista machine. I think I had to do it as administrator. Did you try that (right click on icon, choose Run as Administrator)? You may also have to run the game as administrator after installation as well.

Good tip, but aren't all (or at least all the older) GOG games (and their installers) set to run as Administrator automatically?

Are they now? Because I do remember having to do this with this particular game. It's been a while - I think 2 years - since my Vista machine, and things may have changed since then.

Try here.... https://www.gog.com/forum/heroes_of_might_and_magic_series/homm2_not_at_all_working/?search=setup%20file

If that does not work, use this forum, and post your question there. Also contact GOG Support for assistance, and they will help out as well.

Hi everyone, thanks for all the suggestions.

I still couldn't get it to work on my desktop but I was able to get it to work on my laptop with Win 8 so for now, at least, I can play.

I believe your problem is "User Account Control" UAC. There is a way to turn it off, otherwise, many of the GoG installers would take forever to start up on Vista. I recall waiting almost 10 minutes on my old machine for some games. They will start to install, there is just this insanely long pause before they do. And clicking on the setup again, just makes it worse, as you are now trying to install yet another copy...

So, two options for you...click once and just wait...or turn off UAC and it should be snappier...

So its quite clearly that Vista is the problem, as usual. There really is no need/reason to use it as its widely regarded.as.one of the worst operating systems ever developed.

Sometimes the UAC prompt takes a long time to appear with GOG installers, then when it finally does it won't get focus and eventually just disappear if you don't notice it on the taskbar.

Watch the taskbar for the GOG installer icon to appear, if the UAC prompt doesn't come up automatically just click the icon on the taskbar and you should be good to go. I've had that happen a lot on Vista & Win 7.