the ACPI driver is something to do with power management. Have you installed all the drivers form the acer website? your best chance is probably to contact Acer support.
I have installed all drivers from Acer website and this "Unknown Device" still shows. Two drivers I need earlier weren't available on the Acer website and I had a time hunting down drivers, one I needed from this intel site for the ethernet controller and I had another from another site so I'm trying to figure out which driver I need for this one. Acer Support won't support because PC is out of warranty and will cost heaps for them to do anything and their only answer is the send the PC for them to re-image the PC and that costs $400AU. Might as well put that towards a new PC.
Hi, I got the same problem with a Scaleo E, Chipset 915G.
What driver did you use? I can't find any for Windows 7!
Check if in the bios there is an option to disable Infra Red (CIR).
Otherwise, go on to the manufacturer website, look if there is any driver for Infra Red for Vista or Seven. If this is only for vista, try to run on compatiblity mode.
All the best,
I don't want to disable infrared, ir seems to be ok.
I solved the problem bij installing an AMD AwayMode driver for Vista
I found one from Dell: http://www.downloadatoz.com/driver/download_61281.html
No more unknown device for me