Many thanks all,
as you probably guessed its all a bit new to me, one week so far.
I have taken on board about Knoppix being a CD Demo, and indeed did try to install Debian but got a lot of SU error messages when I clicked anything re the system.
I have downloaded the DVD (5.3) and have just booted successfully from it, and the onboard LAN works.
I will now re install Debian onto the hard disk. Will report progress.
Meantime thanks for the response,
again, this is a great help
Cheers,
David
ps the sound works now also

Update 6pm GMT
Well, its certainly been a learning curve, one hard disk too small (only just), another loaded ok but then would not reload, and finaly had to bring out a 250gb sata (but with a 20gb partition).
So far so good, did sort out the su thing, have youtube and BBC weather (player), but no way to play music cd's (yet).
OK just one thought.... I think/hope the firewall is active, I am behind a router, but should I consider other measures in the near future?

Thanks again