Thanks so much again, jadz! Instead of a normal Drive C:, under This PC in File Explorer I have Windows-SSD (C:), which is identified as "Local Disk." From there I was able to create a new folder under my username.
When I then right-click on the OneDrive icon > Settings > Account and click Choose Folders, the new folder is not on the list. Does that mean it would be safe to put my large files in (whenever they've completely downloaded)?
Under Settings > Account > Choose Folders, there is also another folder that was there before called New Test Folder for Troubleshooting. It is unchecked for syncing. Maybe that folder would be safe?
When I left-click on the OneDrive taskbar icon, I see my Outlook Profile.pst uploading AND downloading, very slowly, with almost 14 GB to go in both instances. My Outlook program has not been opened/used for more than 12 hours.
Archive.pst is also uploading on the list even though I removed it from Documents > Outlook Files this morning after it had completely downloaded from OneDrive and put it on my external hard drive D:.
Discouraged but grateful for your help,
Veazy