Just go to this List of Hardware Drivers, find the Aspire one, and run each driver installer.
The latest Windows drivers for Atheros WLAN card is not avaliable from Acer, but from http://www.atheros.cz/ The Aspire One have Atheros AR5007EG card installed, so it is this driver you want.
- The driver download process from Atheros.cz can be a bit tricky. Some users have experienced problem downloading with Internet Explorer, and you have to wait a few seconds for the Download Dialog to appear on other browsers.
- To install, right click on netathw.inf and select Install.