I run mine on Vista Ultimate X64.
First thing is to try installing to the C:/Program Files directory and Not to the C:/Program Files(x86) one.
That helps alot of problems.
Second, of course open as Administrator or set in the properties (right click) to always open as admin.
Just make sure everything is up to date, never hurts.
Make sure if you are useing voice recognition it is configured right and set and installed right.
And it could always just be a bad install or misregistered dll somewhere.
But it does work.