For starters, I would highly advise you to switch device drivers for your network card. In most cases, Windows XP will detect and load its own drivers which usually work with problems, but could also decrease your performance. When problems start arising, the first thing I recommend, is to download and install the latest drivers available from your maker's product.
After having that done, check to see if you are still having the problem – if so, launch the Event Viewer application and look for any errors relating to your network card. If you do happen to find any, the next step would be to visit Microsoft's support page.
If you do not find any errors, then I'd look towards the switch. If it's a smart Layer 3 switch, there could be a possibility it has been configured incorrectly or there are some other problems with it. Lastly, to be on the safe side, change your UTP cable as well.
This was first published in October 2004