This information can be foud here.
Quite Basic process to reset a CIsco 2960G switch back to factory defaults if you don’t know the passwords of the switch:
- Hook up a console cable to the Console Port and use Putty or other serial client to view the Console session
- Hold down the Mode button on the front of the switch and power it up
- When the SYST light stops blinking, let go of the SYST button
- You should see the switch booting up in your console session
- When presented with switch: type flash_init and hit enter
- Once it finishes loading, you need to delete some files in the flash. List the files by entering dir flash: (don’t forget the : at the end)
- Delete the config by entering del flash:config.txt
- You may also have VLANS set up on the switch, so you need to delete that info as well, del flash:vlan.dat
- Now type boot and hit enter to reboot the switch
That’s it. The switch will now go through a factory default boot up, and ask you if you want to configure it further.