Win 8.1 to Win 7

I have numerous programs that will not run under Windows 8. Most are specialized applications for industrial engineering use. Quite expensive to upgrade ($1000's) especially when little benefit is gained except for it running on new PC's. Also have several custom written applications. They won't run under Windows 8 because Microsoft changed several technologies they relied on. Microsoft has never thought backwards compatibility is something of importance. Their view is out with old technology, in with new, better gizmos. For me, I want reliability, stability, continuity etc but that doesn't get MS a constant money stream. My company has about 150 PC's, a few Windows 8, quite a few Windows 7, numerous XP, 2 Windows 98 and about a dozen running DOS...yes, DOS, all networked together.