Yes, it's the OS's fault that there was no solution given to run old software that doesn't need any upgrade or newer OS features to run with full functionality. The fact of the matter is, when I benchmark my software on Windows 98SE w/64MB and Windows XP w/1GB RAM, it runs better on Windows 98SE.
Well if you have win7 64bit pro. And your CPU has hardware virtualisation then you can download XP mode for free which includes a copy of winXP
If you have more basic version or like me your CPU is pretty old (AMD64x2) and doesn't support hardware virtualisation then you can just use the free microsoft virtual pc 2009 and install a copy of your own xp disk.