Upgradig Cisco IOS on Catalyst Switch/3750 using CLI from Local Computer.

Assign IP to VLAN iterface to your switch e.g VLAN1|

Switch(config)#interface vlan 1
Switch(config-if)#ip address 192.168.100.10 255.255.255.0
Switch(config-if)#end

Assign IP of same subnet to you local PC

192.168.100.5/255.255.255.0
no need defaulg gateway

Verify connection

Switch#ping 192.168.100.5

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.100.5, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/203/1006 ms
Switch#

Download, install,RUN TFTP server on local computer

Copy the latest firmware to TFTP directory.

Check the flash available memory space, about 20MB is free.

Switch#show flash

Directory of flash:/

    2  -rwx        2072   Mar 7 1993 00:09:32 +00:00  multiple-fs

    8  drwx         192  Apr 14 1993 14:17:45 +00:00  c3750-ipbasek9-mz.122-46.S     E

32514048 bytes total (20837888 bytes free)

Start copying and provide the source file name

Switch#copy tftp flash:

Address or name of remote host []? 192.168.100.5

Source filename []? c3750-ipbasek9-mz.122-55.SE7.bin

Destination filename [c3750-ipbasek9-mz.122-55.SE7.bin]?

Accessing tftp://192.168.100.5/c3750-ipbasek9-mz.122-55.SE7.bin...

Loading c3750-ipbasek9-mz.122-55.SE7.bin from 192.168.100.5 (via Vlan1): !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[OK - 12098366 bytes]

12098366 bytes copied in 280.692 secs (43102 bytes/sec)

Switch#

OR

Copying with scp

Switch#copy scp://username@192.168.100.5/c3750-ipbasek9-mz.122-55.SE7.bin flash:

Existing Boot IOS info

Switch#show boot

BOOT path-list      : flash:c3750-ipbasek9-mz.122-46.SE/c3750-ipbasek9-mz.122-46.SE.bin

Config file         : flash:/config.text

Private Config file : flash:/private-config.text

.

.

Changing the Boot to new IOS image

Use command in global config boot system flash:/ in 

Switch#conf t

Enter configuration commands, one per line.  End with CNTL/Z.

Switch(config)#boot system flash:/c3750-ipbasek9-mz.122-55.SE7.bin

Switch(config)#end

Switch#show boot

*Mar  1 00:34:25.308: %SYS-5-CONFIG_I: Configured from console by consolet

BOOT path-list      : flash:/c3750-ipbasek9-mz.122-55.SE7.bin

Config file         : flash:/config.text

Private Config file : flash:/private-config.text

..

Reload/restart switch

Switch#reload

System configuration has been modified. Save? [yes/no]: no

Proceed with reload? [confirm]

*Mar  1 00:38:56.025: %SYS-5-RELOAD: Reload requested by console. Reload Reason: Reload command.

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Delete OLD IOS

Switch#delete /force /recursive flash:c3750-ipbasek9-mz.122-46.SE