|margia, You're probably using Norton 360. The link below explains those icon overlays and how to deal with them.|
A check in a green box means the file’s backup is current, while a chevron (») character in a blue box indicates a file that’s been changed since its last backup. Files excluded from the backup set display a slash in a gray box.
If you don’t need the backup indicators feature you can turn it off by clicking Settings in the Norton 360 main window, disabling the Backup Status Indicators check box and clicking Close.
Green Tick or Blue Arrows Icon Overlay Displayed for Files in Windows Explorer
The link below has a picture of icons with the ovelay.