During installation of Ubuntu 12.10, my wireless worked. Post-installation Network Manager showed "Wireless Disabled by Hardware Switch".
Long story short I had to black-listed the acer_wmi module.
Add the following at the end of the file:
sudo nano /etc/modprobe.d/blacklist.conf
Reboot and if all goes well, the wireless should work.
# Acer Wireless Module
This solution should apply to Gateway laptops [manufactured by Acer] and Acer laptops.
Note: I've noticed in other post people not able to find the *-wmi module, try an underscore instead, *_wmi.