How does it not open? Is there an error message?
When I did version checking, it was running on a all of the machines that I have: Win2k, WinXP (SP3), WinXP64, Vista (and I'll do Vista64 one of these days).
The only thing I can think of offhand is that you might have obtained the 64-bit version and are trying to run it on a 32-bit system.