First of all, I apologize for posting a Windows XP question in the Windows 7 forum, but the XP support forum responses, one by a MS Support person, both directed me here for my answer, and the only current XP forum in TechNet is specific to the installation of SP3. Over that last two months, I have run Windows (XP) Updates manually on many of my clients' Windows XP Pro systems that had gotten somewhat behind on updates (~100 - 200 MB per PC, critical & optional updates combined), and some of them have lost some DNS client functionality. Out of perhaps 75 computers updated, five have had this problem, but it is quite severe when it occurs. Specifically, after the updates, these things fail: IE8 (Page cannot be found), cannot resolve DNS names when pinging, and cannot access resources on network shares. However, in every case, nslookup does work to resolve names, I can ping LAN and Internet IP addresses, DHCP client works fine, and I can open websites and network shares using their IP addresses instead of URLs. In NO case has any of the following resolved the problem: netsh int ip reset, netsh winsock reset, netsh winsock reset catalog, manual removal of the winsock registry entries & subsequent reinstallation of TCP/IP. In one case, one of the MS Fixits (50202 or 50203, I believe), resolved the issue, in another, the winsockxpfix EXE worked. In two cases, both of these also failed, and I was reduced to running a Windows XP repair installation, and I have one more in front of me now for which my last resort will also be a repair installation. There has got to be a simpler answer for something that is obviously just something corrupt in TCP/IP, yet not resolvable by the above means. How can I test to determine the specific file or function that is failing, and how can I resolve this issue without a Windows repair installation?

Hi Brian, This document gives you an idea of what an winsock reset entails. http://windowsxp.mvps.org/winsock.htm That said, I am surprised that the machine would not work past an IP stack reset. Might sound silly but do your computers have Skype or Quicktime or Safari running because they can install the bonjour service which can cause the addition of a static route to 0.0.0.0. This document talks about that http://support.microsoft.com/kb/970313. Also, http://www.howtogeek.com/howto/6456/what-is-mdnsresponder.exe-bonjour-and-how-can-i-uninstall-or-remove-it/ talks about removing the service itself. Again my response is based on assumptions but this is something that I saw in my environment after some updates so thought it might be the same issue. -Good Luck.