Windows 7 - Lost internet connection suddenly, Can ping but no browsing

I was working with internet like usual, Suddenly it stopped browsing websites. I can ping but browsing doesn't work.

OS : Windows 7 Ultimate 64-bit, System type : PC

Internet Connection : The PC gets it's connectivity through the laptop. In other words I am sharing my laptops wireless using a ethernet cable with my pc.

Solution 1:

Here is what you should do to fix this problem: ( Special Thanks to Psycogeek )

1. Install MalwareBytes, Update, Do a full system scan.
2. Install Microsoft Security Essential, Update and a full system scan.
3. If you have any Norton AV product, Uninstall it using Norton Removal Tool. There is a high possibility that it might block web traffic.
4. Open cmd and run sfc /scannow
5. Update your network adapter drivers
6. Enable Telnet client (Google it if you don't know how), open cmd and run telnet www.google.com 80. Check the output and see if you can connect to it or not. If there is no message at output there is a possibility that you have problem with cables or hardware components.
7. Try to ping some domain names you never have visited before. And ping some IP address directly. If you can't get reply you probably have DNS problems. You can also give DNS address manually in your adapter settings. Don't forget ipconfig /flushdns
8. Keep enabling/disabling network adapters, rebooting system and using "Diagnosis" feature of windows while doing all these tests.
9. Try to run netsh winsock reset and netsh interface ipv4 reset and netsh interface ipv6 reset in cmd. Make sure to reboot to see effects.
10. Undo any registry tweaks you have done before to your network interfaces.
11. Download TCP Optimizer latest version, Run it and choose your network interface and speed. Click either Windows default/Optimal setting and apply it. Be sure to tick the registry backup. Reboot and see changed
12. Check your browser proxy settings. Make sure you are not using a global proxy and try to see if you can reach web using different browsers. don't stick to one.
13. Make sure Netbios is enabled in your network adapter settings.
14. Try to disable anything other than Internet Protocol Version 4 (TCP/Ipv4) in your adapter setting to see if something is wrong configured.
15. If you are on a DHCP network, check if Obtain DNS Address Automatically is ticked.
16. Go into safe mode with networking to check if you can reach web in there. Or try another user. It might be caused by a specific user.
17. Use CCleaner to check all startup items and disable unnecessary items. Some services or programs can cause this, report says one of them is Bonjour Service
18. Open Run, execute services.msc and check if all network-related services are running.
19. Open browser and check if you can open a https website ? This problem might be caused on a specific protocol like http or port 80.
20. If you have a HUB switch like mine, Try to swap ports. It helped in my case. Check if cables are not cut.
21. This also can be caused by some kind of worm or malware which is undetectable by any AV product. So try to check your process running in task manager, analyze eachone and try to end process those suspicious exe files.
22. Check your HOSTS file located in windows/system32/drivers/etc/ It might be you're pointing all domains to localhost.
23. Check the 13 Network adapter items in Device manager, for disabled or failing Driver/service items. Different ones are needed for different connection types.