Yesterday, after quite some time, I managed finally to enable the wireless networking on my Acer Aspire 4320 notebook using ndiswrapper. At first I had tried aceracpi, which I couldn't manage to make work, probably caused by my inexperience. Next I tried madwifi, but no luck either. Finally, I tried NDISwrapper, and after some time managed to get the wireless network up and running on the Aspire.
Today I installed Ubuntu 7.10 (Gutsy Gibbon) again on my notebook, and followed the steps to get the sound, and microphone work. The reason for this is that I wanted to document each step of making Wi-Fi work using NDISwrapper in an easy to reproduce way.
As shown in Updating Ubuntu after Installation, a restricted driver "Atheros Hardware Access Layer (HAL)" gets installed by default on the Acer Aspire 4320. From what I understand this is a (very) outdated version of madwifi, one that doesn't support the wireless hardware present in the notebook.
Since NDISwrapper makes it possible to use a Windows wireless network driver the three following steps are required:
Note: I have reordered some steps I've made to keep this tutorial as clear as possible.