To reset Cisco switch you need console cable and ready telnet application
First to reset Cisco switch, unplug it from power
next hold MODE button
and power up switch
wait wile switch powers on and in telnet will be boot log.
When switch booted with holded MODE button enter in terminal command flash_init
Next delete configuration file, to do it run command:
delete flash:config.text
Accept with "y" that you agree to delete configuration
next try to delete vlan configuration file if it exists, run command:
delete flash:vlan.dat
Accept with "y" that you agree to delete vlan configuration
Last one restart switch with command reset
Wait while switch boots up and show to you System Configuration Dialog
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