If I may add, Obduction will run on a pretty high-end game engine (which was developed by a big game company), which means it'll be much more demanding for older PCs and older versions of Windows, since it's tailored for high end PCs with a recent OS, good graphic card, processor, lots of memory, and all that. Don't expect to run Obduction with a PC that was bought with XP on it, even though Uru runs fine on it.
Yeah, I'd say using Windows 7 or 8 is a good solution. Windows 8 really looks weird at first, but you get the hang of it eventually - once you've found how to display the desktop, that is
Using XP does have its advantages though: you still get the echo effects in the game, which were completely broken when Windows dropped support for EAX for Vista-and-above OS. Plus, some of the older games are quite tricky to get to work on newer OS - personally I've managed so far, Uru works great but I've spend quite a lot of time making realMyst work. Myst 1 was quite a trouble on 7, I didn't even try on 8.
And yes, it's annoying to have to buy a new OS - or even a new PC - when things are working fine already. Plus lots of people simply can't afford it, that's sad but that's how it works