What methods have you tried? Being from a techy background all i can give is just some basic advice as i havent dabbled with the software that much asuming your using VagCom?
VagCom is a very basic software written program with certain limitations to what you "can do" and what you "can't do" in my opinion. Can ask are you using the full version?...that might be 1 technical hitch as in the demo version you can't really do anything with it tbh.
Secondly which is most probably the case its down to a hardware fault (meaning your serial usb adaptor) isnt being recognised by the software (VagCom) because VagCom is just meant to recognise simple OBD II cables along side the corect drivers installed BEFORE VagCom.
Thirdly i would sugest searching the internet for a driver for the serial connector although this may sound silly but serial leads were around alot longer before USB and although they were designed back in the day to work as plug and play, software written programs (VagCom) as such have moved on from this and cannot regognise the hardware link between your serial connector and usb meaning now it makes it alot harder.
Sorry if i may have baffled you with my technical babble but hopfully this might be able to point you in the right direction
...just look on the serial connector for a make and modle number and let google do the rest of the work lol.
