This might not be something you can accomplish on your own. I would contact Acer and see if they can help you out. There might be an update you can do to fix the issue.
So, I didn't listen to Acer and I upgraded my A0A150 to Windows 7. Everything runs smoothly except for the fact that occasionally it drops all wireless connections and cannot find them again unless i turn off my netbook and start up again (restarting makes it forget that it has a wireless drive all together).
The driver suggested by Acer online is Atheros AR5007EG (which is not compatible with Windows 7). So I installed Atheros AR5008X which is supposed to be compatible with Vista / 7. Everything was going fine until recently when I started having the same problem as before. And last night things really went wrong. Now no matter which driver I use my netbook cannot find any networks (I tried reinstalling the driver from the Acer website, and even tried other Vista drivers).