Hi, I'm new to these forums and I apologise for repeating any previously asked questions, and for my ignorance!

I am looking at building an HTPC over the next few months, I have built computers before but never for such a specific purpose; and I have limited experience with TV tuners and the media software that has been recommended by posters on these forums.

I do want to build a robust, functional, silent system; and while I'd like to keep things as cheap as possible, I am happy to pay extra if it means better longevity/functionality.

At the moment I would appreciate clarification of the following:

1. Operating systems: I have a copy of windows XP professional; which I can transfer from an old currently unused computer to the new HTPC to avoid the extra cost of buying a new OS. Will this limit me in the future, or should I really look at buying a copy of Vista?

2. TV tuner cards: very few cards have advertised the ability to "record in the original hi-definition H.264 format", and most state they will record in Mpeg-2 quality. Since I will be getting a video card capable of hardware H.264 decoding, will this ever matter?

3. TV tuner cards: currently the card which would appear to suit me best is the Hauppauge WinTV-NOVA-T-500 because it will let me record one channel while watching another (I watch terrestrial freeview). However in the future I will look at adding a DVB-S receiver as I will be interested in receiving some foreign channels (optus satellite). Would adding a second TV tuner card be unlikely to cause interference and would it be easy to configure for independent use in software?

4. TV tuner cards: are the external cards such as the WinTV-NOVA-TD-Stick as good as the internal cards?

5. Some HTPC cases come with remote controls: is it generally easy to transfer all functions of the TV tuner card onto the case remote and vice versa?

Thanks so much for anyone who helps answer these questions :)