3750-x switch is having an advanced feature for rommon recovery. for other switches we used to do xmodem recovery. for 3750-x switch we do not have to waste time like that.
follow the procedure, we can set the ipaddress even in the rommon prompt and transfer the image
Step 1 Connect your PC to the switch Ethernet management port.
Step 2 Unplug the switch power cord.
Step 3 Press the Mode button, and at the same time, reconnect the power cord to the switch.
You can release the Mode button a second or two after the LED above port 1 goes off. Several lines of information about the software appear with instructions:
The system has been interrupted prior to initializing the flash file system. The following
commands will initialize the flash file system, and finish loading the operating system
software#
flash_init
boot
Step 4 Initialize the flash file system:
switch: flash_init
Step 5 Connect the switch to a TFTP server through the Ethernet management port.
Step 6 Start the file transfer by using TFTP.
a. Specify the IP address of the TFTP server:
switch: set ip_addr ip_address/mask
b. Specify the default router:
switch: set default_router ip_address
Step 7 Copy the software image from the TFTP server to the switch:
switch: copy tftp://ip_address/filesystem:/source-file-url flash:image_filename.bin
Step 8 Boot up the newly downloaded Cisco IOS image.
switch: boot flash:image_filename.bin
http://www.cisco.com/en/US/docs/switches/lan/catalyst3750x_3560x/software/release/12.2_55_se/configuration/guide/swtrbl.html#wp1099467