Which Synapse should I reinstall?

I was having some issues with my fanning running all the time and Support gave me detailed instructions about removing Synapse and a number of other files with an eye to a completely new install.

I uninstalled Synapse, but none of the other files I was to remove existed on my computer and at that point I thought I'd better get some help.

I posted about this here a while but I've never been able to locate my post to see if I got a response. I've just scrolled through the posts here today and I still can't find it. I have Watch this thread and receive email notifications, and I never received an email so I assume I never got a response. I don't see a way for me to find my posts, either.

So here I am, with no Synapse on the Razer Blade 15, and I would like to at least just reinstall it, if nothing else. The computer is running well, apart from the fan issue, so I might as well just reinstall Synapse and get on with it.

I see there is a Synapse 2 and a Synapse 3? Which one of these should I download, and are there specific installation requirements?