Backup AND Restore Cisco Router config to USB flash drive

First and foremost, you will want to have your console or remote session connected to the router before doing any of the following steps; this post assumes you know how to do that.
Backup

• Plug the USB flash drive in and watch the console session to see what the flash drive is identified as

• most often, something like usbflash0 or usbflash1

• You will want to format the flash drive if it isn't appropriately formatted already so

• format  usbflash0:

• you will have to hit enter to [confirm]

•  Next, you will copy (backup) the startup config to the drive:backupfile

• copy startup-config usbflash0:backupconfig

• you can then copy this file from the flash drive and put it somewhere safe; multiple somewhere's safe at best 

Restore

•  Plug the USB flash drive in and watch the console session to see what the flash drive is identified as

• most often, something like usbflash0 or usbflash1

• List the backup files on the flash drive

• dir usbflash0

• note the name of the backup file you want to restore from

• Restore the backup file to the running config

• copy usbflash0: run

• will ask for source/destination

• source: file name noted previously

• destination: just hit enter    

***Don't forget to write your config to make sure changes are saved