Hello,
Unfortunately there is no way to recover a lost pin number or reset the pin from outside the OS. You will need to perform a factory reset of the device from outside the OS by following these steps:
- On your Surface Duo, press and hold the Power button, then tap Power Off. Note: If you’re prompted to reboot to safe mode, select Cancel, and repeat this step.
- After your Surface Duo is powered off, press and hold the Volume down button, then press and release the Power button. Continue to hold down the Volume down button.
- After a menu appears, release the Volume down button.
- Press and release the Volume up or Volume down button to change the menu. The menu you want to select is Recovery mode.
- Press and release the Power button to select Recovery mode.
- On the screen that shows a small robot lying down (with the words “No command” underneath), press and hold the Power button, then press and release the Volume up button. Release the Power button.
- On the Android Recovery screen, press and release the Volume up or Volume down button to change the menu.
- Select Wipe data/factory reset, then press and release the Power button.
- Press and release the Volume up or Volume down button to select Factory data reset, to confirm this is what you want to do and then press and release the Power button.
- On the Android Recovery screen, press and release the Volume up or Volume down button to change the menu.
- Select Reboot system now, then press and release the Power button.