I am using Acer Aspire 3680. I recently reinstalled Windows Vista, and the wireless did not work by default. I installed the "Atheros Wireless LAN Driver" on this site: http://support.acer-euro.com/drivers/notebook/as_3680.html

The result, the wireless APs are successfully scanned. However, when I tried to join a network, even with 5/5 signal, an error message showed up diagnosing signal too little. I restarted as Ubuntu, and wireless worked perfectly, with same computer position. Even more confusing, When I moved to the kitchen (2 meters close to the router), the wireless connected, when I move back to my room, wireless failed on Vista and worked on Ubuntu.

It is clearly the driver problem. Acer laptops seems come with pre-installed drivers, but after re-installation, they are all gone. (I can't find the original Acer backup disc)

Please do not answer "move closer to the AP" and something related to "interference", as wireless worked with Ubuntu's default driver.