Onboard sound means that it has a sound chip built onto the board which can be used
Sometimes this is quite good, sometimes it is appaling. Depending on your situation you may want to use your own sound card
You can change this in the BIOS (Press DEL at start - you know what I mean I'm sure
) . It will all be in the manual which comes with the motherboard
External modems are better and probably only 10 quid more than an internal modem, just grab anything for a modem. To be honest I don't know the difference between a good and crappy one. (Would like to know please...
)
HTH, Thanks,