Microsoft Office Picture Manager has a Picture Shortcuts pane that shows a list with the Recently Browsed folders. While creating my video Micro Tutorial here at Experts Exchange showing How to Install Microsoft Office Picture Manager in Office 2013 (by utilizing Microsoft SharePoint Designer 2010), I discovered that Picture Manager itself does not provide the capability to delete items from the Recently Browsed folder list or to delete the list in its entirety. Fortunately, there's an easy way to do it outside of Picture Manager. This video Micro Tutorial explains the method.
1. Locate the OIScatalog.cag file
Open Windows/File Explorer or whatever file manager you use and navigate to this file: