Wi-Fi adapter dropping conection?

I keep losing internet conection every 10-15 min and it says limited so i run troubleshooter and it fixes it and says default gateway not available its annoying having this happen constantly i have the latest drivers instaled fixed power managment settings to not turn the wireless adapter off and tried a few other things, i'm running win 8 64 bit on a lenovo Z580 laptop anyone any idea of what could be causing this?

Try to reset the Wi-Fi adapter and reconfigure as

limit it to 11-20 mbps
range must be 20 meters.
and the must important thing to avoid interference with other Wi-Fi devices and radio signals reduce it to 4 or 5
set up a strong password and done.
enjoy unlimited internet connection without dropping it again and again and again…

If it happens on all the networks that you connect, I would look at computers' Wi-Fi adapter. If not probably troubleshoot from AP/Wireless Router point of view for distance, band, & interference.

Wi-Fi is not perfect. Depending on where you are sitting, where the Wi-Fi router is located, what is in between these 2 points, what is near the router, even the angle of your laptop screen ( that's where your Wi-Fi antenna is at) is at, all can affect Wi-Fi reception. Even other Wi-Fi networks can be the cause. Are you connecting to a 2.4Ghz channel or a 5Ghz? The 2.4 Ghz frequency is also used with cordless phones