I'm going to file a support ticket too, but has anyone had an issue installing the game with the Windows 7 Offline Installers?

I keep getting a corrupt file error at the same point in the install. One of the files unpacked in temp isn't correct.

I tried to install twice off one set of installers and once off a fresh download of them and fails at the same point in install every time. I'm curious if this is a me problem or if the offline installers need to be reuploaded on GoG's end.

Did you already do a https://www.gog.com/account/refresh ?
Sometimes solves those kind of issues too.

Can't test the installation via the offline installers myself right now but plan to do a playthrough during the upcoming holidays, so having the offline installer packages in working order would be certainly appreciated.

I downloaded and installed them and had no problems.
The integrigty-check was o.k. and the game runs fine.