I appreciate all the input and comments. However, at the risk of seeming extremely stupid, I most cases, I haven't the slightest idea what you're talking about.
As for VM, I think I originally said I tried to get WinXP to emulate an earlier OS, Win98 in fact. Never worked and I'm sure I did something wrong, but couldn't figure out what. And that was quite awhile ago. As for the Mobo OS switching, as I also said its been or 7 years, or more since I last bought a machine or paid any real attention to what's out there. I know I don't know a tenth of what goes on technically any more, if I ever really did.
Full Disclosure - I once worked as a system administrator on UNIX token ring systems. Hated it, and it was only half as difficult to understand as Microsoft's stupid OS'es. I moved into systems analysis and UI development as quickly as I could. In truth, given good explanation, I understand technical issues, but am NOT a techie at heart. And ever since leaving sysadm, I've vowed to have as little to do with hardware as possible. Call it my personal blind spot. Oh, yea. I also worked for Microsoft as an analyst and project manager, in IT not the retail side. Most screwed up company and development concepts on the planet. Except for their business plan of selling a new version every 18 months with or without useful improvements, which even that they messup more often than not.
Without spending alot of time thinking about all this (or knowing about the MB OS switching), I figured that I could just swap hard drives in and out of a bootable external bay as easily as anything else. Everything, and only, what I wanted or needed with a particular OS would be on that drive and nothing else. This was especially important for keeping the AH game drive completely clean. No other programs or exposure to the Internet in any way. Seems simple enough, especially for my simple mind.
My biggest concern was that there might be a reason why this plan would NOT work. Or that my components were not compatible, or had a too short technical life expectancy. I used to get new computer every two years (when I had money) and this last time its be nearly 7 years. Too short and too long. I'd like my new machine to have decent performance life of 3 or 4 years if possible. Also, running older OS'es would be a nice extra, but is not critical. The real idea was to keep by business/personal side of computing, all the programs and the Internet separate from my AH gaming.