I think the prescribed medicine for your system is a Windows XP Repair
Install. This should re-implement the Network Properties
There is an excellent tutorial on how to do this (and other XP-related
fixes) on Harry O's Windows XP "New Life For Windows" website:
"How to Repair Install: (also called "In place reinstall")
Sometimes the only way to repair XP is to reinstall. You do not have
to wipe your partition and start over. Just as with previous versions
of Windows you can install over top of an existing setup. This has the
advantage of retaining your installed applications, data and settings.
You will lose previously saved System Restore Points but System
Restore will begin creating new restore points again immediately
following the Repair Install. You will need to reinstall SP1a and any
Critical Updates from the Windows Update Site.
*** Be aware that a Repair Install will leave your system vulnerable
to the Blaster and Welchia worms. Do not go on line until you have
enabled XP's firewall first. Then visit the Windows Update Site to
patch your system. ***
It is always prudent to backup important data before you make changes to XP..."
I also highly recommend that if you have not already done so, you
download and run the following free programs, not just for this
problem, but on a frequent basis (every few days, weekly, or monthly,
depending on how much surfing and download is done on your system):
Spybot Search & Destroy
*** IMPORTANT ***
If you already have Spybot and/or AdAware installed on your PC, be
sure to download the latest updates first **each time you run them**.
Other helpful free anti-scumware utilities:
Something to keep in mind is that even if these programs give your
system a "clean bill of health", it does *not* mean that you can be
absolutely sure that your system is clean. It is only a *reasonable
assurance* that it is clean.
I definitely recommend that you install Zone Alarm or Zone Alarm Pro.
I (and many people I know) use the Pro (paid) version, which provides
more extensive protection and customization. You can download them
It's also VERY important to continue to check with Microsoft
periodically and make sure that you have installed any new
security-related patches that have been released.
You can find out if there are any available by going here:
Before Rating my Answer, if you have any questions or problems with
the above information or need assistance in performing the
identification and removal procedures, please post a Request for
Clarification, and I will be glad to assist you.
I hope that this Answer helps you to resolve your nasty problem, and
that you have smooth surfing once again!