Windows Backup and Boot

[Dave]

I want to back up my computer on a  2 tb USB. I also want to include my ext hard drive on the back-up. How can I do this?  Also, can I use this back-up to reboot my pc should it go down?
Thanks

[ngc2392]

You mean complete backup like image backup? I would suggest many free software as easeus, cobian, aomei (https://www.lifewire.com/free-backup-software-tools-2617964)
why would you backup external drive? it's allready on "backup" location. Next step is cloud based backup. And, yes, with most of previosly mentioned programs you can restore "image" of your system. Which you can daily backup in incremental backups.
I recommend that you backup only important things like pictures, documents etc. Anything else is mostly waste of time on external drive. But, it's your choice, of course

[patio]

The partitions should be seperate images...