Upgrading the IOS on a Cisco Switch

First remove the old IOS

delete /force /recursive flash:directory

Setup TFTP with Tftpd32

Run command on telnet

enable

archive tar /xtract tftp://172.20.10.30/c3560-ipbasek9-tar.150-2.SE8.tar flash:/c3560-ipbasek9-tar.150-2.SE8

Once completed

config terminal

boot system flash:c3560-ipbasek9-tar.150-2.SE8/c3560-ipbasek9-tar.150-2.SE8.bin

Show boot

show boot

Save the config and reload

wr mem

reload

To verify the IOS

show version

To verify the boot

show boot

Source: http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst2960/software/release/12-2_58_se/configuration/guide/2960scg/swiosfs.html#wp1257481