Can't install over

A general setting with Windows is that you can't install an older version. If you have XP Svc pack 3 and something craters, you can't do a repair with a Svc Pack 2 install disk, etc. There may be a special downgrade disk for business computers purchased with downgrade rights (don't know), but there's no such thing for "regular folks".

I went from 7 Home Premium to 8 Pro on my main home machine and used Classic Start Menu to give it the "look and feel" of 7 except I left the slide-out right-side menu (which Classic Start Menu can disable). I found 8 still was somewhat unwieldy. Things a power user can do in 7 keep refusing permission in 8 or you have to "jump through hoops".

After awhile, an unrelated hardware problem caused a total crash. For some reason the good backups just wouldn't reinstall. I reinstalled 8 (no other programs), but then thought, "Wait a minute! I like 7 better! Even though I can make 8 look the same, 7 is a bit more stable and less of a hassle!" So I wound up reinstalling 7 onto a different SSD instead and then loading all the other programs.

Incidentally, when I wound up upgrading my spare computer, I just stuck in the Win 8 reinstall I had done. I use a KVM switch, so both computers have the same monitor and keyboard. Because it wound up with a look and feel almost exactly like 7 after booting, I had to set a different theme so I don't get confused as to whether I'm in 7 or 8.