Just finished the back-up. While I was backing up, I got a pop up message that said "Windows detected a hard disk problem. Back up files immediately, etc. Replace or repair the hard disk." So I haven't done anything else yet. I read that this could be malware on my system made to look like a real system message. Or the obvious likelihood that my hard disk is failing. I'm guessing both options are pretty bad.
Unfortunately I'm leaving town and won't be able to address this further until Tuesday. Thank you for your help thus far! If you have any recommendations for what I should do next when I get back into town I would greatly appreciate it. I guess I'm not sure whether this is an Avast-related issue anymore. Thank you!!