I'm not sure why, but MW4 hates newer equipment, and can easily have trouble in Windows 8. Windows 7 or earlier is best.
Windows 8 and on have gradually dropped support for obsolete 3D graphics solutions. They'll do their best to run old games, but if the program asks Windows to check a memory register or run a function through a chip that simply does not exist anymore, Windows will have no idea what to do. Even if you manage to get the old hardware installed in a modern system - good luck - there's fundamental incompatibilities at play.
As suggested, if you really want to play the old games, you're going to have to bite the bullet and build a retro gaming rig. The good news is that the components - even some really high-end bits, for the time - are going to be cheap. The bad news is that you're going to see a lot of hardware failures and will be doing a lot of tinkering. The best advice I can give is to track down "new old stock" items: those that were manufactured during the period but never sold, so they're still in their boxes. Try to avoid components that were manufactured after the technology died, as companies started cutting a LOT of corners to make them as cheap as possible.
But here's the REALLY good news: once you've got a system working, it should be able to play ANY old games, right back to the DOS era. You might need an older version of DOSBox to slow some of the really old titles down, but that's about it.
Just...yeah, don't connect the machine to the internet.