Password Recovery Step for Cisco 2501 router :

  1. Gent into a rommon mode (Boot the router and interrupt the boot sequence by performing a brek [use ctrl+break])
  2. change the configuration register into 0×2142 (by pass nvram)
  3. reload the router
  4. enter privilleged mode
  5. copy start-up config  into running-config
  6. change all password (including privileged,  line, and secret password)
  7. Turn  on all interface
  8. reset the configuration register to default value 0×2102
  9. save your router configuration