hi guys just a quick post to see if anyone can help me with software for my laptop so i can use obd2 usb plug to diagnose faults in my xr8 5.4

Depends.

If your using an AU, FORSCAN is free and actually works.

Im sure it supports the BA BF etc as well. I use it for all my fords with a bluetooth OBDII tool

Nigel

For my FG, I use an macbook. I downloaded Movi Pro from iTunes. It expensive (Around $100) but it reads and clears the codes. It also runs and records live and stores it to your hard drive so you can look at it when you have finished driving (need to have the laptop and scan tool running while driving). It also has graphs for easy reading and can display 4 parameters at the same time while recording up to 40 different parameters.
It is a US based program but they cover most vehicles in the world and customer support is really quick to respond back!

forscan works right through to FG