well... not familiar with Virgin Engineer visits but I would reckon that the engineer would have a device that tests the connection anyway>? I doubt they would need to use YOUR pc to make sure THEIR service is working? what happens if a customer has a faulty network card and its dropping the cable connection?? Virgin cant test it cos they dont have a device to do so?? ...no, I think the rep is probably just confused, unless they insist so they can 'force' crapware onto your PC installed by the engineer ??
NOTE: Its not fibre cable, its copper cable... unlike Virgin would have everyone believe, didnt Samuel L. Jackson say "superfast fibre right into your home"..? lol Virgin Cable is similar to BT's FTTC except that is uses better quality copper cable from their cab's with RF Amplifiers en route which boost signal. the cable is a Co-Axial fitting on end (similar to satellite dish cable, same end) , it fixes into the SuperHub off which you can use LAN or Wi-Fi