has anyone got a spare webcam they don't need? either cheap or free please

When you say cheap do you mean very very very cheap?
You can buy a brand new one for less than a tenner

Got a couple here, but not necessarily Win 7 compatible though.

I have a boxed Logitech C250 webcam you can have for a fiver.

Or an unboxed Logitech QuickCam Communicate STX you can have for free, just put a couple of quid in the next Lifeboat charity box you see.

where abouts are you please