by Hard Reset
Before you buy a new cell phone or new tablet, please try the following procedure to repair your device. First charge your battery, backup your important data if possible and in most cases take out SIM and SD card before 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.!
Nokia N900 soft reset
Nokia N900 reset
To reset the device from time to time for optimum performance, power off the device and remove the battery.
Nokia N900 restore
Restore a backup
1 Select > More... > Backup.
2 Select the desired backup and Restore.
3 Select the data types to restore.
4 Confirm that you want to restore the data.
If the backup is password-protected, enter the password,
and select OK.
5 If your device contains a newer version of the files than
the backup you are restoring, the device asks you to
confirm if you want to save the backed up version, or
cancel data restore. Select from the following:
Yes — The device overwrites the current version with
the backed up file.
Yes to all — The device overwrites all conflicting files
without further confirmation.
No — The version on the device is not replaced.