Windows 7 - Bad internet access via wireless connection Win 7 64

I have a problem with internet access when connecting wirelessly on ONE Win 7 64 laptop on ONE router. The same laptop connects to internet just fine to ALL other routers, while ALL other computers (with different OS) connect to internet just fine via this router.
The laptop in question connects well to the router itself and you can red everywhere that it is connected to internet as well. But when i try to load any pages in any browsers i get "server not found" in FireFox or "This webpage is not available" in Chrome. Email and torrent clients don't work either.
This does not seem to be a DNS issue because accessing sites via IP address does not work.
Pinging any sites or IP addresses does not work.
The strangest thing is that the situation have been worsening slowly over last 2 weeks - at first everything was just fine, then i would have to reload pages every now and then, last days i would succeed less and less frequently and as of yesterday - no luck at all...

Anyone has any idea what this could be?

Wireless card : Atheros AR9285
Cable modem with router: Cisco EPC3925

Welcome to Seven Forums Starko,

Do you have the latest driver for your Atheros?
ATHEROS drivers for Microsoft Windows (Atheros?????)

If you have not done this yet, please remove all wireless profiles stored in your computer.
Easy Way to Delete Wireless Network Profile in Windows 7
Re add your SSID (wireless network) that you're trying to connect to with the correct encryption.

If none of the above suggestions worked please install and run Xirrus Wi-Fi Inspector from one of your wireless computers. Double click the Xirrus Icon on your Desktop, Tap the Printscreen key on your keyboard, open up Paint then choose Edit from the Menu and select Paste, then SAVE it. Upload and attached the file here.

Also, please post an ipconfig /all for review. Here's a tutorial.

Please post an update.