If your graphics card has video in (like the ATI All-in-wonder cards) then yes, otherwise as Gavin says you're going to need a capture card of some sort. You'll also need a SCART to Phono (or SVHS) cable and if you don't already have a spare SCART socket on your cable box/video recorder a SCART splitter.
If you have a good freeview signal, you might be better off buying a USB freeview device for the PC (I bought a DEC 2000T from SCAN for £23, it's on offer quite often).
http://www.scan.co.uk/todayonly/
DW