Guys, I solve this issue on my Windows 8.1 computer. Before this way of solution my internet speed was terrible and it disconnects around 2 hours periodically. After his way of solution I haven't encountered any problem (since October 2014). I hope this will also solve yours.
I have HP TouchSmart 14 laptop, which has Intel 7260N wifi driver. This device also has bluetooth integration inside.
- Put your computer to flight mode and DO NOT DEACTIVATE IT UNTIL THE LAST STEP (THIS IS VERY IMPORTANT)
- Plug the ethernet cable and download the latest wifi and bluetooth drivers of your computer
- Uninstall the former drivers (both bluetooth and wifi) and reboot.
!!VERY IMPORTANT!!
After uninstall, open device manager and check again if there is any wifi or bluetooth adapter driver exists because even you uninstall it for once Windows starts to use previous one that was installed way before. So uninstall everytime until you see something like "Generic driver" (Network Adapter section on device manager) or there is no any option to uninstall on the drivers menu (to see it right click on the driver), we are sure that there is no any driver that may conflict with the one we are going to install.
- After you are sure that there is no any driver exists, please install the new ones that you downloaded from ethernet cable (I recommend you to install bluetooth one first)
- After you install both of the drivers the computer will ask you to restart, accept it (between those two the computer may ask you for reboot dont accept it. Please continue and install which one is remained.
- When the computer rebooted, activate your wifi driver (go off from flight mode)
- Go to device manager- Network Adapters right click on your wifi adapter and click properties
- Go to Advanced section and Click HT Mode and change it to "Disabled"
- Click UAPSD Support and change the value as Disabled
- Go to Power Management section and remove the mark from "Allow the computer to turn off this device to save power"
- Click ok and restart your computer.
I hope this solution works. Also, I don't think that it's driver manufacturer's fault. If most of the computers have the same issue on the same "new" operating system then this is Microsoft's fault. Since English is not my native language there may be some mistakes, I'm sorry for these.
See you:)