How can i set all the settings back to factory default? The Express Setup and Resetting the Switch do not do the job. What is the way?
I haven't got a 3750 to hand but I think this should work:
Type 'show switch' and determine the switch's number (that it used to be in the stack). Then renumber it using the command 'switch x renumber 1'. Then reload the switch.
As for the VLANs remaining I thought removing the VLAN.DAT file would solve this, however it may be different with 3750 stacks.
Telnet or console into the switch and enter 'enable' and the password (if any). Then type following commands:
Erasing the nvram filesystem will remove all configuration files! Continue? [con
Delete filename [vlan.dat]? y
Delete flash:n? [confirm]y
Then either type reload or power reset the switch and it should reboot at factory default. If the config register has been changed or any parameters changed from ROMMON then you would need to correct these as well.