Hi,
I realise this isn't a cheap solution but if you get one of the Tx to USB interfaces it makes a Tx appear to be a standard joystick to ANY pc program so with a single interface you can control almost all r/c sims (and almost all PC games in fact) and the nice thing is that, apart from the first issue of Win95 almost all subsequent versions of Windows have USB support so, on the whole, it doesn't matter what version of Windows you have (or if you upgrade from one to another).
I've got the USB-JSIM from Ken Hewitt at
www.rc-electronics.co.uk and think it's a great little interface.
Cliff