So you have reinstalled Windows on your ROG Ally handheld PC and now you have an unknown device in the Device Manager.
When you open the properties to see the details, it says something about an ASI device, apparently from Nvidia, and also mentions something about NPCF. This seems a little odd since the ROG Ally is an all-AMD device. It has an AMD processor and an AMD GPU built into the processor—nothing from Nvidia. Well, not quite.
ASUS ROG Ally has a so-called XG Port, which is used to connect external GPUs, and apparently, that requires Nvidia drivers. To install drivers for this device, you will need to download the latest Nvidia graphics drivers from the Nvidia website. Just select any recent Nvidia GPU and download the driver.
When you launch the installer, it will first start to unpack the drivers. Pay close attention to the path where the driver is unpacked. After the installer finishes unpacking, it will check your system and display an error message stating that the Nvidia installer cannot continue since no Nvidia GPU has been detected. This is expected. Do not close this window yet.
Follow the path where the drivers were extracted, usually the Nvidia folder on the C drive. Continue opening the folders until you reach the “International” folder. Inside, you will find a folder called “NVPCF.” Copy this folder somewhere on your PC, such as the Downloads folder. Once copied, you may close the Nvidia installer window, which will also automatically delete the Nvidia folder on the C drive.
Now, go back to Device Manager, right-click on the unknown device, and select “Update driver.” On the next screen, select “Browse my computer for drivers.” Click “Browse,” navigate to the NVPCF folder you copied earlier, select it, and click “OK.” Then click “Next,” and Windows will successfully install the Nvidia Platform Controllers and Framework driver.
After completing these steps, the unknown device will disappear from the Device Manager, leaving everything neat and tidy.