For a fee, Microsoft will upgrade your Win7 Home to a version that will run XP mode.
Have you confirmed that you need XP mode? My Win7 Home 32 runs every XP and DOS program that I have. At work we have Win7 Pro 64bit and it DOES require XP mode to run some of our older (16 bit) programs.
I believe I need XP Mode. I run pcanywhere 12.5 and it does not work with Windows 7. The version I have is Windows 7 64-bit.