You really should wait at least 24 hours on these forums. They are not very active this time of day/night.
Anyway. Try some or all of this:
eth0 shoudl be the device you network with. To check this:
sudo /etc/init.d/networking restart
sudo dhclient eth0
It should produce a result similar to:
eth0 Link encap:Ethernet HWaddr XX:XX:XX:XX:XX:XX
Just saw it was for wireless, so replace eth0 above with wlan0:
ifconfig |grep wlan
Don't know how much more you want to "reset" the network.
sudo ifconfig wlan0 down
sudo ifconfig wlan0 up
All user settings and files are stored under: /home/username
So backing this up will save all the files (user related and created) and most settings.