Follow this procedure to clear the memory from your Yakumo delta 200:

1. Backup your information if necessary.
2. Disconnect all cables, including the AC adapter, from your Yakumo delta 200.
3. Stop all running programs by tapping  Settings - System tab - Memory icon - Running Programs tab - Stop All.
4. Use the stylus to slide the ON/OFF switch to the OFF (up) position.
5. Wait for 1 minute and then slide the switch back to the ON (down) position.
6. Your Yakumo delta will automatically turn on and prompt you to start the setup wizard.
7. Follow the onscreen instructions to complete the setup wizard.
8. Reestablish a. partnership with your desktop computer.
9. You may also want to restore data to your Yakumo delta from your most recent backup file.

NOTE: If the battery completely runs out of power and is not charged in time, you will get the same result as you restore the factory default state.
Yakumo Delta

General advice: Before you buy a new cell phone or new tablet, please try the following procedure to repair your device in a software way. First charge your battery, backup your important data if possible and in most cases take out SIM and SD card before doing factory reset. It is impossible to recover your data after doing a hard reset, so online backup is always important. For all of your data, a backup should be done on an external device, hard drive, raid system or media. With or without insurance, if your cell phone lost, damaged or stolen at least your invaluable data is backed up in a safe place. If you are about to sell your phone and you want to wipe your personal data, or if your phone affected with virus you have to do a hard reset. In some cases, you can delete the forgotten password or lock pattern from your device as well. All information is for devices with stock based ROMs. If you are using rooted device, always back up your EFS folder first, containing your IMEI info, etc.! Please also note, that a hard reset operation will not unlock your mobile phone's SIM lock or network lock, but it will remove the unlock pattern, remove the user password or PIN password (NOT the SIM card's 4 digit PIN code). Also note that the firmware version will not be affected in any way, it will not be downgraded, it will remain the same you are using and if you have rooted your device, root privileges remain also unaffected.