how to restore factory setting of Mikrotik Router:
Resetting a Mikrotik router is almost similar to other routers. You simply need to press the reset button with pin or with some niddle. Following are some easy steps for resetting a Mikrotik router.
1. Use a ballpoint pen to gently press and hold the res key, do not let go
2. Then turn the power on.
3. After the device is powered, power light and ACT lights light up; continuing to hold the reset button do not let go , after the ACT LED flashes, immediately release the res key. (Note: for 750GL reset: After the device is powered, power light and ACT lights light up; continuing to hold the res do not let go until the ACT lights off on the release of a key res.)