Friend of mine bought dell latitude 7450 which came with window 8 Pro, but because the guy is in love with Linux he installed Deepin Linux (http://www.deepin.org/) a linux distro based on Ubuntu, soon after installation he started facing problem of wifi disconnection which was so bad as sometimes the wifi forgets the password so he was supposed to retype the password every time it disconnects.
We take as challenge, and starting working with on it, where we discovered that the computer come with Intel Wireless 7265 card which has problem of loading the wifi driver in Ubuntu and all Ubuntu derivative distros.
The solution is to reinstall the drivers manually, by following the below two simple steps.
1. Download the kernel driver from this link (https://www.kernel.org/pub/linux/kernel/projects/backports/stable/v3.18.1/backports-3.18.1-1.tar.xz), although the driver is based on kernel version 3.18 but it works well also for kernel 3.13 ,and save it to desktop, then run the following commands,
sudo apt-get install linux-headers-generic build-essential
cd ~/Desktop/backports-3.18.1-1
make defconfig-iwlwifi
make
sudo make install
2. Download the firmware from the following link (https://wireless.wiki.kernel.org/en/users/Drivers/iwlwifi#Firmware), from documentation they suggested to use -9 for kernel version 3.17 but because we have kernel version 3.13 we downloaded both -8,9 and 10, download them on Download folder and extract then run the following commands,
cd ~/Downloads/iwlwifi-7265-ucode-23.11.10.0
sudo mv iwlwifi* /lib/firmware
cd ~/Downloads/iwlwifi-7265-ucode-25.228.9.0
sudo mv iwlwifi* /lib/firmware
cd ~/Downloads/iwlwifi-7265-ucode-22.24.8.0
sudo mv iwlwifi* /lib/firmware
sudo chmod 644 /lib/firmware/iwl*
Reboot your computer for the change to take effect.
Problem solved, Enjoy!
For more info, also check the following links
http://ubuntuforums.org/showthread.php?t=2261834
http://en.community.dell.com/support-forums/laptop/f/3518/t/19627199
