Okay so I had the exact same problem. The thing is the solutions you tried may have been causing the problem in the first place. I was not able to access netflix.com or pcmag.com. My computer was the only one on the network that couldn't do it. Two other computers on the network could access those sites, so i was perplexed. I called my cable internet company (Road Runner, Very nice and helpful) and wasn't able to resolve the issue. Then I called the router company (D-Link, worst customer service I have ever had, plan on discouraging everyone I know that isn't a network guru from buying D-link.) Neither could help, so I dove deep in several related searches, and through inductive reasoning, guessing, and divine power, okay just kidding, eventually I got everything up and running smoothly.
The problem:
Using any browser at any settings, still cannot access certain websites, still able to ping the website through the command promt, just no browser action
The Cause:
The winsock registry value being modified by either ad/spy ware or a firewall, you see when the spy/adware was removed from your system, as it should be, the registry values that it modified are still modified, certain ad/spyware specific registry values are removed, but ones such as winsock, remain altered by the malware.
The solution:
First clear all malware. Second turn off/uninstall all firewalls, and even turn off windows firewall. If you are behind a router there is a hardware firewall protecting your pc so there is no need to worry. next you will be editing your registry so for the love of everything back it up first. It is so easy to completely destroy your computer doing this that it is well advised to back it up. Now manually editing your registry is the scariest thing a pc user can do in my opinion, so i recomend a handy little program that i found on line that will fix the problem you have straight away. download winsockfix.zip from
http://www.tacktech.com/display.cfm?ttid=257
be sure your registry is backed up and then run this program. you will need to restart your computer then do so now. make sure all firewalls are turned off. in my case virus protection was left on, and still worked fine. you dont want your firewall to start up on the reboot, so make sure it is disabled. that worked for me and it seemed we had very similar problems. i hope this works for everyone else. or that anyone else even reads this. remember back up your registry do it. it is simple
best of luck,
Jordan