Just a suggestion - But check the proxy settings of the browsers. Whenever I've noticed that my browsers have no internet access, but some other applications still do, and i can ping etc. It's sometimes down to proxy settings in the browsers being altered somehow. Also try installing Chrome and see if it loses access as well when the others do.
On a hunch I installed Chrome. Same thing happens!! Arggggh!
Can you give more details about the Proxy setting, pls.?
But..on the positive side.... I "Think" I may have solved the problem.
It's been more than 12 hours since I did these changes...I'm just not sure which of these changes was the potential trigger:
1. Found a startup file that looked very, very suspecious. It was called Webcheck...it was a delayed start progarm...but it did not seem to have any affinity to Windows. It just didn't feel right...sorry for the non-technical expression.....so I removed it.
2. On another hunch, I initialized all my Norton Firewall settings.
so far so good. Has the problem been solved???...well I haven't had to reboot for 18 hrs....
So far so good. Heres where the proxy settings are, check these whenever your access isn't working to see if anythings changed, as far as I know, for a normal home pc, these settings should more or less be blank and not be using any proxies. The last pc I looked at that had lost connection had proxy details entered into these settings by a trojan.
Tools -> Options -> Advanced -> Network Tab -> Settings -> make sure set to 'No Proxy'
IE (8) ------
Tools -> Internet Options -> Connections Tab -> LAN settings -> Make sure no Proxy server is selected
By the way, on further Inspection it seems chrome also uses IE's network settings. :\
I quickly googled webcheck. I saw some conflicting info on it, some saying its a util from m$, and others saying its malware. If you've deleted it and all's well tho. no worries :) Good luck.
Frustrating. I thought I had fixed teh problem..but..no. Still happening (not as frequently though). I did manage to get the following oytput from TCP Spy:
the next process to start and make a socket call will be spyed process attached, command line='"C:\Program Files (x86)\Mozilla Firefox\firefox.exe" ' socket (572) created [family=AF_INET, type=SOCK_STREAM, protocol=IPPROTO_IP, dwFlags=WSA_FLAG_OVERLAPPED] socket (572) enabled its nonblocking mode socket (572) could not be bound [name=127.0.0.1] - WSAENOBUFS (An operation on a socket could not be performed because the system lacked sufficient buffer space or because a queue was full) socket (572) closed; bytes received=0, bytes sent=0 socket (560) created [family=AF_INET, type=SOCK_STREAM, protocol=IPPROTO_IP, dwFlags=WSA_FLAG_OVERLAPPED] socket (560) enabled its nonblocking mode socket (560) could not be bound [name=127.0.0.1] - WSAENOBUFS (An operation on a socket could not be performed because the system lacked sufficient buffer space or because a queue was full) socket (560) closed; bytes received=0, bytes sent=0 process detached
It appears that TCP (?) is out of buffers ....WSAENOBUFS.
I was having the same problem - could not access the internet with any browser, but could ping the internet (yahoo, google, etc.) and I could see other PCs in my home network.
After much research (and many unsuccessful attempts to fix), I decided to uninstall my Norton Internet Security (which didn't seem to be working correctly after a delightful automatic patch from Windows). When I rebooted after the uninstall, I was able to access the internet. I reinstalled Norton and everything continued to work fine. Good luck to the rest of you who've had this extremely frustrating problem...