Did you call tech support, it's toll free:
800-517-3001
I have it on 2 XP machines, no problems, a LOT of people have it on SI, no problems reported.
You need Microsoft .NET Framework I think version 3.5 on your machine, but Jing will recognize if you don't and install it for you.
I would call tech support, the wait times are very short for Jing support.