Old computer first.....
What E-mail applicaton are you using?
If Outlook Express check account settings. Your ISP provider can supply the correct settings.
How is it set up? One way is to use a router. Another is to use Internet Connect Sharing. This is the Hwd side.
For software... Was the network wizard in XP run?
New build... How much training does your son have? Not a knock, but the reboots suggest system is overheating and that you are using an Intel CPU. Incorrectly attaching the heat sink/fan will cause CPU to over heat. Also type of case used may cause overheating.
Also Fire wall is not enough protection. You will need all the security patches from M/S and anti-virus appllication.
Overall this is all I can offer at this time. Please read the tip section over where you post. This will give you the information we need to assist you.
Have Win XP Pro & Office XP. I have just gone on broadband, my son has provided me with a new faster computer, I have a firewall ADSL modem. I now can't send out email from my old computer, (but it receives some email)
I can't network with the new computer it says I don't have permissions! The new computer although connected to the net says it can't find remote server, though I have logged into the box, in fact I am in a complete mess and don't know where to start. The new computer keeps rebooting itself every half hour or so.