Asus P552W hard reset

Press and hold UP key, then press RESET at same time. Press Call key to confirm, End key to cancel.

Via System restore P552W

This option allows you to restore the device system to its default factory settings.
To restore default settings:

1. Tap > Settings > System tab > Default Settings.

2. Enter ‘1234’ in the Password field and tap OK to confirm that you want to restore to default settings.

3. Tap Yes to start restoring.

WARNING: This option deletes all files stored in your device. Back up your important data to your storage card or computer before restoring to the default settings. Before proceeding with restoring to the default settings, ensure that you remove the microSD card from the device