Delete / Erase Password on Cisco 801, 802, 803, 804, 805, 811, and 813 series routers
Step 1: Hit ctrl / break directly after powering up the router.
Step 2: Type set at the boot# prompt. Your router will show you a table with different points. list you the set ios-conf point. For example: set ios-conf =0x2102.
Step 3: Type set ios-conf = 142 at the boot# prompt, alternatively 141.
Step 4: Type boot at the boot# prompt in order to initialize the router. Now the router will reboot, but ignores the saved configuration.
Step 5: Would you like to enter the initial configuration dialog? [yes/no]: answer NO.
Step 6: Type enable at the Router> prompt.
Step 7: Type "configure memory or copy startup-config running-config".
Step 8: Type show running-config.
Step 9: Type configure terminal to change or remove the password from the router.
Step 10: Type enable secret <password> in order to change the enable secret password or type NO ENABLE SECRET to remove the secret from router(config)#>
Step 11: type: NO ENABLE PASSWORD to remove the password from router (config)#>
Step 12: Type the no shutdown command on every interface that you use.
Step 13: Type config-register <configuration_register_setting>. For example: hostname(config)#config-register 0x2102 .
Step 14: Hit Ctrl / z or end to leave the configuration mode.
Step 15: Type write memto save the changes.
Step 16: Type reload.