Backup two internal drives onto one external drive

Sure is - you can backup as many drives as you want to a single drive as long as there is space to support them.  The key, is to create different backup tasks for each drive with a unique backup name.  I woul recommend you store each backup in its own folder too - if nothing else, it keeps it cleaner.  

By default, Acronis settings for a new backup are for "enitire pc".  Techncially, this will already attempt to backup all internal drives in one backup and that's what it was designed for.  HOWEVER, too many people get confused by this and it leaves less flexibility for recovery as well.  My personal preference has been to change "entire pc" to "disks and paritions" and create a single, full disk backup for each drive with it's own, seperate task.  That way, you know that backup is always meant for just that one drive.  After that, when the backups are created, it really doesn't matter where they go as long as there is space, the backup names are unique and the backup drive is always online and available before the backup job is run.  

Thanks! That's nice to know. I've never backed up a hard drive before so there may be important questions I'm not asking, or maybe I'm asking stuff that's awfully basic, but for now could you tell me what the process would be for restoring either or both of these drives if the need arose?

Basically, you'd use your offline bootable recovery media to boot into Acronis outside of Windows.  You'd pick the recovery options, navigate to the backup file and select it.  YOu'd then select the destination drive to restore that image to and that's really it if you're restoring an image to the same hardware.  You could easily test this be removing the original hard drive and restoring the image to a different drive for practice.  That way, if anything goes wrong, you just pop in the original drive without worry of accidentally overwriting it or something else while you practice.

Check out these videos...

02 - SunGod2009 - How to backup and restore using Acronis True image - YouTube

04 - Britec - How To Restore Windows 10 from a System Image - YouTube

More good videos in the sticky as well... https://forum.acronis.com/forum/117004