I have games and programs that I used on XP 32 bit that I put on Win8 64 bit with no problem. Jewel Quest 2, Cubis Gold, Bookworm, Richochet Recharged, Moroff Ware Games, Rolling Marbles, Rummy 500, Solitaire Plus, all installed and worked just fine, as did my screen saver program, Webshots. Many of those I had also used on Win98.
Some games that I put on that were used on Win98 before I used them on XP, like Moroff Ware Game, were actually designed for Win95 and Win3.1, and they work just fine.
One program, my music player Sonique, gave a notice when I started to install it that it had compatibility issues, but I gave it a shot anyway. It installed fine and it works just fine, no compatibility issue whatsoever..
A couple of games, like Zuma and Jigsaw Galore, would not install, but I did a google search for newer versions that would work with Win8 64 bit and found them. I had to buy them again but I found a site that had them for such a low price that I didn't mind buying them again. Spent less than 10 buck to get both of them.
My older versions of Quicken and Wordperfect would not work so I had to buy the new versions but so far, of all the stuff I had used on XP 32 bit, there are only 4 program/games that I have had to replace.
In case you can't tell, I skipped Vista and Win7, lol