Hello tdehan, my name is Marco and I am an Independent Advisor. I will do my best to help you.
Try this...
-Press Windows key and type: gpedit
then press " Enter "
-In the left side of Group policy editor, click to expand User Configuration > Administrative Templates > Windows Components, then open File Explorer.
-In the right pane, double-click on "Turn off the display of thumbnails and only display icons" to edit it.
-To display thumbnails preview, select "Disable" option.
Or
-In the Windows start menu type: disk cleanup
-Choose the hard drive where your OS is located ... Generally the C:
-Under the "Disk Cleanup" tab, select the "Thumbnails" options and click OK.
After confirming the deletion, you can close and re-open the files to check if it is fixed.