My PC connects to the router through wifi and is set to automatically find IP and DNS. My PC tells me that it is connected, and, sometimes it says that it has Internet Access, and sometimes not.
My other devices (iPod and Android phone) are connected to the router and DO have access to internet. In the router settings, in WAN section, it appears my ISP IP. My PC isn't blocked by MAC filtering.
It isn't a DNS issue since I can't connect to the internet by IP or hostname.
I've tried with the firewall disabled.
I've reboot my PC a couple of times.
I've uninstall the drivers of my wireless card, and reinstalled it again.
Now it keeps showing me that it IS connected and does have internet access but can't access any website, only the router webserver.
EDIT: I've rebooted the router from the web server (because I don't have physical access to it) and worked just for 5 minutes!
EDIT 2: I've rebooted the router again and It worked but has just died again. I repeat that it only happens in my computer. I'm writing in my iPod connected to the same WLAN.
EDIT 3: I've solved it. I'm not sure why. A week ago I had enabled the Statistics on my Tp-link TL-WR941ND router, and I also had enabled DoS protection because I read this,
"Note: FLOOD Filtering will take effect only when the Traffic Statistics in System Tools is enabled."
so I thought I should had to enable that feature for security since I had just enabled Statistics.
Now, I've just disabled DoS protection and Statistics, and it started to work fine. Rare.
Besides that, I would like to keep using Statistics.