What can I do if I forget TP-Link DSL modem/router login username/password?

The TP-Link DSL modem/router default login username and password both are “admin”.If you or someone had changed them but you forget them now, the only way to access the modem/router is to reset the router to factory default settings.
Note: If you reset the device, the device will return to factory defaults, you will lose all your settings.
Step 1 Turn off the router.
Step 2 Press and hold the reset button on the rear panel with a pin, then turn on the router. (Do not release the reset button when you turn on the router and Please keep holding the button for about 6~10 seconds after turning on the router).
Step 3 Release the reset button and wait for the device to reboot.

Note:
1. Make certain that the router is powered on before it restarts completely. 2. The default IP address is 192.168.1.1, and the default login username and password both are admin (all lower case).
3. Ensure that the IP address of your computer is in the same subnet with the device. It means that your computer should have an IP address 192.168.1.X (X is in range of 2~253), and the subnet mask is 255.255.255.0, the default gateway should be 192.168.1.1 which is the IP address of the router.