Microsoft has a free download for Vitural PC. With this program running in your Windows Vista 64 bit environment, you can run a Windows XP 32 bit environment, and launch an MS DOS environment from there. Additionally, you can create as many of these virtual environments as you want.

Unfortunately, Microsoft requires you to have both a Windows XP licience iand a Vista Licence if you are going to run both Vista and XP (even with one in the virtual world). If you own a regerestered copy of XP, I'm told that a work around to this potential problem is to reinstall your virtual XP environment when the preceeding one experies it's 30 day registration requirement.

Good Luck!

To run the software that won't run on 64-bit I recommend doing as Mike and many other have said:

"Download virtualbox from Sun for free and run a virtual instance of win xp 32bit, win vista 32bit or even just a freeDos system to run your dos programs.

alternatively you can try dosbox, and open source project that run dos programs on other platforms. i know it works on 32bit but i have not tried it on a 64bit system."

Please do not ask the question again, the answer is already written out for you.