1. Turn the phone off.
2. Press and hold the Escape key and the Power button together until the phone vibrates.
3. When the BlackBerry logo appears, release the Escape key.
4. Press Alt + R.
5. Type in the words “blackberry” (without quotation marks).
6. Press Alt + E.
7. Select “Yes” to erase all data and reset the phone.
8. Press the Escape key. 9. Press the Reset button.
10. Wait while the phone reboots.
hard reset blackberry curve 8900 by menu
1. Turn off your BlackBerry Curve 8900.
2. Press and hold the Escape key, the letter ‘R’ key and the letter ‘S’ key at the same time.
3. While still holding the Escape, R and S keys, press the Power button to turn the device back on.
4. When prompted, select the ‘wipe’ option that appears on the screen.
5. Confirm the reset when prompted.
6. When the reset is complete, power off your device and then turn it back on.
7. Your BlackBerry Curve 8900 has now been successfully reset.
how to soft reset blackberry curve 8900 by button combination

To soft reset a BlackBerry Curve 8900, press and hold the Alt + Right Shift + Del buttons simultaneously. This will cause the device to restart.
Note: This will not delete any of your information saved on the device.
Shah Wajahat is a Computer Science grad and a Cisco CCNA certified Professional with 3+ years of experience in the Tech & software industry. Shah loves helping people with tech by explaining to layman audience technical queries in an easier way.