Hi BRL,
What might be worth doing is a Ping and / or continuous Ping test to a variety of addresses.
First of all, open a command prompt (cmd in the Run box) and do a tracert to
www.pprune.org. Note the IP address of
www.pprune.org (67.201.16.181)
When that is complete, note the first (or 2nd) IP addresses in the sequence - the first will probably be a 192.168.x.x, assuming you have a router between your PC and the cable modem. The second (or first, if no router) will be associated with an address like [xxxx-xxx-xxx-xxxxx.cable.virginmedia.com].
That's your "next hop" device. When your internet connection fails, ping your router (if you have one), then your "next hop" then an internet site (e.g.
www.pprune.org), then the IP address of
www.pprune.org (67.201.16.181).
Also, go into the properties of Outlook Express and note down the name and IP address of your mail server (smtp.blueyonder.co.uk or some such). By doing a ping to the mail server name you should get the IP address.
When the connection "fails", try pinging the mail server name, and then the address only.
Let us know what pings are successful and which are not.
Also, can you paste up your PC's network settings? IP address, etc. Is it receiving IP address and DNS servers automatically?
SD