I am new to linux,  I installed debian.  Now I am worried how will my wifi adapter will work on it. I found a thread https://ubuntuforums.org/showthread.php?t=1806839 but didn't able to install linux-firmware and sudo apt-get install linux-headers-generic build-essential also didn't work.It doesn't know about linux-firmware and other thing. Here are errors while installing above things:root@debian:/home/love# sudo apt-get install linux-headers-generic build-essentialReading package lists... DoneBuilding dependency treeReading state information... DonePackage linux-headers-generic is not available, but is referred to by another package.This may mean that the package is missing, has been obsoleted, oris only available from another sourceE: Package 'linux-headers-generic' has no installation candidateroot@debian:/home/love# sudo apt-get install linux-firmwareReading package lists... DoneBuilding dependency treeReading state information... DoneE: Unable to locate package linux-firmwareWhile adding repository the following error showed up:root@debian:/home/love# deb http://http.debian.net/debian/ wheezy main contrib non-freebash: deb: command not foundHere are some results of some commands:root@debian:/home/love# uname -aLinux debian 3.16.0-4-amd64 #1 SMP Debian 3.16.36-1+deb8u2 (2016-10-19) x86_64 GNU/Linuxroot@debian:/home/love# lsusbBus 002 Device 005: ID 138a:0005 Validity Sensors, Inc. VFS301 Fingerprint ReaderBus 002 Device 004: ID 413c:2107 Dell Computer Corp. Bus 002 Device 016: ID 2a70:f00eBus 002 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching HubBus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hubBus 001 Device 004: ID 04d9:a0ac Holtek Semiconductor, Inc. Bus 001 Device 003: ID 0846:9041 NetGear, Inc. WNA1000M 802.11bgn [Realtek RTL8188CUS]Bus 001 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching HubBus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hubWhat should I do? 
How to install Netgear WNA1000M- N 150 driver on Debian?
debian;networking;drivers
Open your sources.list:nano /etc/apt/sources.listthen remove the wheezy repo.There is an example here: deb http://httpredir.debian.org/debian jessie main contrib non-freedeb-src http://httpredir.debian.org/debian jessie main contrib non-freedeb http://httpredir.debian.org/debian jessie-updates main contrib non-freedeb-src http://httpredir.debian.org/debian jessie-updates main contrib non-freedeb http://security.debian.org/ jessie/updates main contrib non-freedeb-src http://security.debian.org/ jessie/updates main contrib non-freeSave and exitUpdate your system:apt-get update && apt-get upgrade && apt-get dist-upgradeInstall the firmware-realtek package :apt-get install firmware-realtekReference : Debian-wiki