I recently purchased an Asus 1215n equipped with Windows 7 64bit. The first thing I did was upgrade to Windows 8 since Microsoft is offering a promotional price of $15 until January 2013. Doing so led to some Hotkey driver compatibility issues though (missing Asus ACPI driver error + no working hotkeys), which were a pain to resolve to say the least. I was unable to find a solution on the web anywhere (one that worked anyways), so I had to figure things out myself. I’m posting my solution here in the hopes that it will be useful to others doing an upgrade to windows 8. I imagine that the solution would also apply to other 1215x models (1215b for example) that came with Windows 7 64bit. Im not sure if this solution is applicable to 32bit Windows 7 versions, though you should definitely still give it a try.
After installing windows 8 and logging in for the first time an error message window popped up:
“Missing Asus ACPI Driver.”