: The tablet is officially stuck on Android 5.0.2 Lollipop . No official Android 6.0 (Marshmallow) or higher updates exist for the Z300C.
Asus locks the bootloader on the Z300C. Unfortunately, there is no official unlock tool for the Intel variant. You need to use the fastboot method. Asus Zenpad 10 Z300c Custom Rom
But time is cruel to Android devices. The official updates stopped long ago, leaving the Z300C stranded on an outdated Android version, choking on the bloat of a bloated system UI and security patches that haven't seen the light of day since 2016. : The tablet is officially stuck on Android 5
If you want to move forward, I can help you find the specific ADB commands to remove the laggy Asus apps, or I can look for the latest TWRP recovery image link for you. Would you prefer to try rooting the current software or are you set on finding a full ROM replacement Unfortunately, there is no official unlock tool for
remains primarily limited to stock firmware or minor root-based modifications . Current ROM Availability