Default gateway is not available - Inspiron 5520

Hi, I'm here because I have a problem with the network driver that is that every time that I use the laptop, the laptops change the connection to limited and the internet simply doesn't work, when I go to network and sharing centel and then to network troubleshooter, it fixes the problem but the problem go back again maybe one hour later, 30 minutes or up to just 10 seconds (I used a cronometer) and that's a big problem because I play online games and I can' t play well disconnecting every  minute, I tried several solutions such as uncheck the power plan, change some driver settings but that worked for several days and then the errors comes back and the solutions didn't work again. If you want information about de laptop just search it on google (dell inspiron 15r special edition 5520) and you'll find all the specifications, just ask me for things about MY laptop, no the serie itself. (I have windows 8.1)