Hi,
This can be caused by a Windows issue corrected in XP Service Pack 2. If you are behind on your service packs, you should install it. You can confirm that you are experiencing the Windows bug by checking your event log for the specific error described
here.
Event 50 with other status codes can be caused by unreliable network connection. If you are connected wirelessly, consider switching to wired or move to an area with better signal. If you are wired, you could have a bad cable. Also, it sometimes helps to disable auto negotiation on the network adapter (let me know if you need help with that).
If this is a school computer, I'd suggest simply reporting it to whomever you would report network issues.
