I had the same problem with exactly the same O/S and capture device. The clue for my problem was the capture was about one frame a second and no AUDIO.
I solved it by going to the capture screen and selecting the 'Capture' menu then 'Device Settings' and changing the audio from the "USB 2863" to my mic/audio jack in ---> perfect captures.
If you PC is still a bit stuttery then you may have to change downgrade the capture 'Profile' to something less demanding like DVD SP