Win7Pro x64, clean install. (not upgrade) Problem began when I was trying to install (&reinstall, &remove, &reinstall) Adobe CS3 to try to get it working. (others have reported no problems with CS3) At some point in the ordeal, I noticed that FireFox no longer worked. I eventually discovered that: IE8 works just fine FireFox (and other Mozilla apps) cannot connect to the Internet Many of the auto-update features of various apps do not work. I checked all the normal things: http proxy, firewalls, A/V etc. No obvious conflicts. I did some Googling, and the sense I got was that this is likely a Winsock problem. I followed the various instructions to reset Winsock and the IPv4 stack, but no success. Before I go to the major hassle of a full reinstall, I was hoping someone would have new ideas. Also feel free to (briefly) reiterate the "obvious" as we all overlook things now and again and it doesn't hurt to be reminded. The machine otherwise seems stable. Thanks.

Well, let's see... I don't know for sure if this is the cause, but it's easy enough to check. Adobe CS3 installs an older version of Apple's Bonjour service which is known to cause networking problems with Windows 7 (specifically DNS issues). You don't by any chance have an Unidentified Public Network suddenly appearing in Network and Sharing Center, do you? If Bonjour is installed, remove or disable it and see if the problem goes away.