All the 32-bit apps that run on Vista or XP should run on Win7 or 8.
Any that balk you should try compatibility mode
. This may work on any 32-bit app.
Unfortunately, 16-bit apps (dos, win3.x, win9x) won't run on 64-bit Win7, but if you install 64-bit Win7 Pro you can likely run them under XP Mode.
Unfortunately, any security vulnerabilities running XP will exist in XP Mode. If that bothers you.
*I am afraid Win8 has no such XP Mode option but you could try running them under XP in virtualization with say VirtualBox.
*Or under dual boot Linux with appropriate Windows emulation apps installed: Wine and PlayOnLinux.
*Or you could set up a dual or triple boot with Win9x and XP, and a bootloader
, but this would require an IDE card with a controller
(supports Win7 and 8
) so you can boot from it and that might be challenging on an EFI setup running Win8.