Thanks Parapunter, guess what, my Virgin Media box is made by .... Samsung!
We have freeview on the TV in the living room and as we don't have a TV in our bedroom where the computer is I thought it would be an easy solution instead of going out to buy a TV for the bedroom. I should have remembered that nothing is easy with Windows!
On thegreenbutton.com I have found out that I need to set WMC up to channel 52 to read my box but it still wants an IR cable. This is very annoying as I am happy to use 2 remotes.
Thanks again, Matt.