When I used my main PC to activate a new Comcast cable modem, it seems that Comcast installed something that does not show up in add/remove programs. Alternately, it's possible that it changed a setting somewhere that I can't find.
Basically, whatever it is is screwing up my dns on this PC and only this PC (all others on the network work fine) and it definitely only started after the cable modem activation.
Specifically, anytime I ping or open a site in a web browser, if the site is not associated with an address or if I haven't done "ipconfig /renew" twice this session on the PC, it usually gets redirected to 18.104.22.168 (which appears to be Comcast's activation website). It doesn't matter if I use IE, Firefox, or just ping from the command prompt. This wouldn't be so bad if the browsers didn't appear to have their own dns cache (eg system redirects, I go do ipconfig /renew and ping now works but Firefox still goes to Comcast (until I restart Firefox)). NSlookup still works correctly (not surprising since it talks directly to the dns server).
Does anyone have any ideas short of reinstalling windows?
If anyone else runs into this, I managed to fix it. Here is what I did to fix the issue (though I'm not sure exactly what worked):
Remove C:\Documents and Settings\All Users\Application Data\SupportSoft
Remove C:\Documents and Settings\$username$\Local Data\Application Data\SupportSoft
Remove C:\Windows\Downloaded Program Files\??? - can't remember the exact filename but if you pull up properties it has a comcast.com (net?) address for the codebase
Remove almost all references to Comcast from the registry - while doing this, I found Comcast overwrote application and window titles/names to be "provided by Comcast" and changed the default homepage in IE
I found the SupportSoft entries because I did a file scan based on the last modified date when I activated the Comcast cable modem and then found some Comcast references therein.
Shoot I be calling comcast and raising hell with them. Bypass the level 1 geeks get either a super or a tech 3.
I would but it's Comcast. We used to have Time Warner and they were good (good internet service, good tv service, good customer service (not that we had to use it much since everything worked)). Then we got screwed when Comcast and Time Warner did their market swaps and are stuck with Comcast. The quality and up-time on everything went down and their customer service is complete crap (the only company I've dealt with that's worse is Qwest (so no DSL as an alternative to cable for us)).