Step 1,

Go to PC world (not normally recommended)

Step 2,

Pick up the £15 freeview tv tuner card

step 3,

Install it...

Step 4,

Plug in monitor.

all done...

Windows should take car of the seperate graphics cards easily, and should treat the freview card as a seperate device...
Not 100% sure of this solution, I just know a mate of mine did a dual screen set up and one was freeview and he just brought a tuner card for it.