Dragon NaturallySpeaking 10.1 products support Windows 7 Operating System (both 32-bit and 64-bit).
No version of Dragon NaturallySpeaking previous to 10.1 supports Windows 7.

And, if you are wondering about Windows 7 XP Mode, the answer is no.
No revision of Dragon NaturallySpeaking supports Windows 7 XP Mode.

For more information please refer to this link:
http://nuance.custhelp.com/app/answers/det...Uag%3D%3D/sno/0