Reset default factory Cisco Switch

1. Connect up your console cable and power on the switch, whilst holding down the “mode” button:

2. Initialize the flash file system with the command: flash_init
3. Delete the config.text file from the flash directory:
4. Delete the vlan.dat file from the flash directory:
5. Reboot the switch and you’re done:

sumber : http://notthenetwork.me/blog/2013/05/28/reset-a-cisco-2960-switch-to-factory-default-settings/