You should run the diagnostic program that came with your network card.

3Com cards normally come with one which is quite good at giving you an idea of the problems it may be experiencing. If you have lost the disc or it didn't have one, then you can download them off of the 3Com website.

Step 1. Ping your network card (open up a DOS prompt and type "ping ").

If you don't know the IP address, type "ipconfig" and read the IP address associated with the PC. If you get any reply times, your card is probably working.

Step 2. Try pinging your router's IP address. Your ADSL provider should have given you this information, or you can find it by looking in the network neighbourhood properties, under the TCP/IP properties for your network card. Again, if you are getting replies, then your router is working.

Step 3. Ping an IP address somewhere on the internet, such as 212.161.108.129, the server where vnunet.com is based. If you can reach an outside IP address, then you have a valid connection to the internet. Finally, ping a domain name, such as vnunet.com. This will tell you that your DNS is working.

Everything should be working normally at this point. If not:

a. The idea is to ping out from your machine, one step at a time, and this will help you determine where the problem is. If you can ping your network card and the router, but nothing beyond that, then you know that your computer is OK, and the cable going from your computer to the router is OK.

b. The problem lies then either in the router or the cable that goes out to the street, or runs to the telephone company, or maybe even their equipment has gone down. The next step is to call your provider and tell them what you have been able to deduce. Make sure that you talk to a proper technician and not just a jobsworth reading from a script.

cIt may be as simple as a cable that your dog has pulled out, but this kind of test will determine where the problem is.