>>>I have a duel tuner card for DTV and would like to add an analogue tuner so that I can tune into Sky which is broadcast over the coax – can you have both in media center and do I need a separate program?<<<
Yes, for the time being, you will need a separate program. I used to use GBPVR. Don't forget, if you have Sky Movies you get free access to Sky Anytime which will give you better quality than an analogue feed.
>>>I have ripped all my DVD to ISO files and would like to play these in MC or convert them or the original DVD to something that will play on a 100” screen which little or no degradation in quality – I know some of this is possible but just haven’t pieced it all together yet. I have done something similar in Apple TV using handbrake to rip the DVD to MP4.<<<
Not sure about ISO's. Media Centre will happily play DVD's ripped to VIDEO_TS and AUDIO_TS folders.
>>>Can you surf the internet from with MC? <<<
There are severe technical limitations in the media centre that make it difficult to build an internet browser that runs within its environment. Anthony Park comes closest with his MCE Browser (See http://www.anpark.com/Software.aspx). I developed my own browser that runs alongside MCE or VMC and which is designed to be operated with just a remote (See http://www.SeeITA.com/TF).
>>>Can you access BBC iPlayer?<<<
See http://thegreenbutton.com/forums/thread/271988.aspx I haven't tried it, though. Note that should BBC redesign their site the addin will stop working. OTOH, my browser will work with the iPlayer, but not inside MCE/VMC.
Andy