How to install a new SSD in your Asus ROG Ally
Once you’re in the BIOS menu, use the touchscreen to navigate to the Advanced tab and select Asus Cloud Recovery. From there, you should be able to follow the prompts to download and reinstall the OS. While you’ll need to redownload and reinstall any games you had stored on the original SSD, you’re otherwise good to go. Good luck, and have fun.