There are several things at play here. 1. As you are undoubtedly aware, Windows 7 has been out of support for quite some time already. Worrying about UF version in this situation feels a bit like putting the cart in front of the horse. 2. While official supported versions matrix is much more strict the actual interoperability range between UFs and indexers is quite big. The s2s protocol changes relatively rarely and connection endpoints can negotiate a version acceptable for both ends. You might eventually encounter some issues especially around encryption (even more likely if you have some strict requirements which older UF might not be able to meet). 3. Since both your Windows version as well as any possibly applicable UF version are no longer maintained you won't be able to get any support regarding any problems with them (as you can see - including installation issues). So the best you can hope for is just try several versions to try to find the one that works if you absolutely can't get out of Win7. It's unlikely that anyone here will have current experience with forwarders on Win7 let alone your particular installation problems.   ... View more