The best to do: contact Acer customer support and ask which driver to use in Windows 8. If no luck, go back to the original configuration of Windows 7, either from the recovery disks you made, or from the 'image' you made before installing Windows 8.
Are you sure it's a driver issue? Did the wireless function correctly with Windows 7? And, of course, there's the possibility that you didn't install some helper app (although that should stay present and active with an upgrade install) or that just incidentally the hardware went south.
I have recently updated my Acer AO 725 with windows 8 official upgrade.
issue i run into recently is my wifi is not working, one problem i had was few of the drivers where not pre available with windows 8 so i had to download them from acer website.
one among them was for wifi-driver. But their are 3 wifi driver available for my device model and when i install any one of them, windows run into a problem.. the blue screen comes and it run the recover mode.
i am not sure what the issue is. i think the wifi driver of my model is manufactured by Broadcome .. also windows 8 boot lil slow too..