VCR is your Capture Source. Win TV is your Capture Device.
1) Enable VCR Input, in Setup / Capture Source. DV (Digital Video) Camcorder is Default. Won't show until Analogue VCR & Win TV are connected
2) WinTV 850 should show in Setup / Capture Device / Video Drop-down. If yes, Select it.
3) Connect VCR & Capture Device, before Launching Studio.
4)If S Video no good. Try Composite cables Connection. 1 Video 2 audio (L & R) from VCR.