mick u should have received new version of datascan in email (im hoping u didnt rip it off someone else...)
usb/serial converters do work (ive got one) - try it with something else though, like serial mouse
give us more info on the car ur trying it on, whether uve tried other cars, whether uve tried other software (scantech nissan is a good freeware one, http://www.geocities.com/obdscantech2000/S...nTechNissan.zip)