Think this has been posted in the wrong area but meh, Yes you can connect NTL to your PC and watch NTL on yout PC.
You need a TV card in your pc then you can connect your STB to the TV card and then use your PC as a sort of PVR (Sky + ish) box.
Example TV Cards:
http://www.ebuyer.com/customer/produ...subcat_uid=715
In the future they will be creating cable cards that will allow you to insert a NTL cable card nto your PC and then plug your coax into your PC and do it that way, but this is "long way off".
Hope This Helps