One thing I've never really seen explained is why 64-bit OSes completely dropped support for 16-bit software; one would assumed that creating some level of 16-bit emulation wouldn't be the hardest thing in the world to pull off.
You write that emulator and get back to us.
Seriously, though, the people in need of sixteen-bit software support are a small niche at this point. Any software serving a practical purpose has been replaced by a thirty-two or sixty-four bit alternative. What's left but games, and where's the monetary benefit in bending your programmers over backwards to ensure that those ten and fifteen-year-old games continue to work? It's why a lot of new drivers are breaking old games, like MechWarrior 3 (tenuous link to the original topic!). It's just not feasible to try to offer infinite backwards compatibility. The investment in getting it to work would grow continuously, and the returns would decrease to almost nothing. It's why your XBox doesn't have a cartridge slot for Atari 2600 games, and it's why Windows 7 doesn't run Commodore 64 applications.
Oh, and nixing support for old software also feeds into the cycle of planned obsolescence. Why, after all the hype, did Microsoft and Sony backpedal so hard on backwards compatibility in the XBox 360 and Playstation 3? Because if you can play old games with the original media, you're less likely to buy the 'HD'-rehash from their digital download service. With Games for Windows Live integrating more heavily into each new iteration of the OS, I imagine Microsoft will be aiming to nick a slice of GoG's pie by offering updated versions of old titles, as they make new operating systems without the backwards compatibility necessary to run those old programs. We've been incrementally upgrading hardware of all types for years and years, and now it seems there's an avenue available for companies to make us incrementally upgrade a wider variety of software in much the same manner.
CP is right about video card drivers, though. That seems to largely go back to companies lacking the time or money to even attempt to test new drivers for all manner of old software, since it's so rare (if it's ever happened at all) to have a PC hardware manufacturer producing or remaking games. Still, if developers and publishers can find a quick and cheap way to patch some of these old games to work on newer systems, they can squeeze another ten dollars out of you, for a game you already own, for which they don't even need to worry about pressing a disc.
RA with certain mods (which worked fine back then) is actually quite unstable on modern systems. It doesn't work properly in Virtual PC either unfortunately.
I had a big paragraph addressing the ease of my experience with Red Alert, but it's a forest-through-the-trees issue. There are a few, specific titles that have trouble with my hardware-driver-OS combination. There are a few more specific titles that have trouble with a newer hardware-driver-OS combination. By and large, though, titles from that era can still be installed and played with relative ease. Certainly, there's not yet enough of a barrier to get them running to warrant the kind of effort on a new emulator that went into DOSBox. Not to say that I'd be sad, if someone with the time and skill decided to make a top-notch Win98+DirectX5-7 emulator, starting today. I just think that the library of unusable software is currently so small that it's quite unlikely someone with the time and skill has decided to act.
* Mongoose apologizes for total thread hijack
Status quo intact.