I'm posting the message content here to alert others in case they're having the same issues:
I brought this up earlier and wanted to provide an update. I archived Supreme Commander on my XP laptop and attempted to transfer it to my Vista desktop. This did not work because the download was OS specific. A previous support email suggested I try archiving via right-click directly to the archive folder before installing. I spent some time with Windows 7 beta and then uninstalled for a switch back to Vista. The Supreme Commander archive is still flagged as being OS specific.
This should not be happening for two reasons:
1. I directly downloaded to archive.
2. I'm running Vista 32 Business. The only change is that this is a fresh install and activation of the OS as well as a fresh install of Impulse after formatting the hard disk.
Please let me know whether this is a problem on my end and if not, let the development team know of the issue. As it is I have to assume that the archiving function is broken as is.
Thanks
The right click option refers to the "download and archive" function you get when right-clicking a not-yet-installed piece of software. Stardock support suggested this option would keep the archive OS independent.