The software is free from ross-tech but the cheap cables off ebay don't allow full functionality - only shareware mode. or only work with old versions like 409 etc.
Only the proper ross-tech cable will unlock and register the software - so you can scan for faults with the cheap one but cant change anything and the codes arent specific in shareware mode.
The proper cable for v607 (latest version) is the vag-com hex usb, and is £220 from ross-tech (thats the one I have)