How to install Ralink WiFi driver on Ubuntu

1. Add lines to file:

sudo gedit /etc/apt/sources.list

deb http://ppa.launchpad.net/markus-tisoft/rt3090/ubuntu lucid main 
deb-src http://ppa.launchpad.net/markus-tisoft/rt3090/ubuntu lucid main 

2. Update and install:

sudo apt-get update
sudo apt-get install rt3090-dkms

3. Reboot

4. Check driver verion in /sys/module/rt3090sta

1. Download appropriate driver from official Ralink site:

http://www.ralinktech.com/support.php?s=2

for our case - RT3090PCIe

2. Unpuck somewhere and do make.

sudo make
sudo make install

3. Copy RT2860STA.dat:

sudo cp RT2860STA.dat  /etc/Wireless/RT2860STA/RT2860STA.dat 

4. Put driver file to the system:

sudo cp os/linux/rt2860sta.ko /lib/modules/2.6.32-30-generic/kernel/drivers/staging/rt2860/rt2860sta.ko

5. Restart network:

sudo /etc/init.d/networking restart

ps: For controling work of the driver look to the /var/log/syslog. The appearence of the problem is presence in the log lines containing «STASendPacket→Cannot find pEntry».

Source How to fix wicd 1.7.0+ds1-5 Connection Failed: Bad Password on Ubuntu 10.10 (Maverick Merkaaat)

ubuntu:~# apt-get remove --yes network-manager
ubuntu:~# dpkg --purge network-manager-pptp-gnome network-manager-pptp network-manager