quote: It's also an awful option for media files on Windows 8, as Win8 doesn't let you add removable media to your libraries, and it doesn't allow ModernUI apps to access files that are not in your libraries. There are workarounds (such as making softlinks to removable drives inside existing directories) but they're a kludge, and not something users should have to go through the trouble of doing/figuring out.
quote: To add a folder to a libraryIf the folder is on an external hard drive, make sure the drive is connected to your PC and that you can open it.If you're viewing the New Library page in File Explorer, tap or click Include a folder, select the folder, and then tap or click Include folder. You're done. If you don't have the New Library page open, continue following these steps.Open File Explorer by swiping in from the right edge of the screen, tapping Search (or if you're using a mouse, pointing to the upper-right corner of the screen, moving the mouse pointer down, and then clicking Search), entering File Explorer in the search box, tapping or clicking Apps, and then tapping or clicking File Explorer.Expand the location to find the folder you want to add, and then select it. (For example, if you want to add a folder from a network, expand the network location and select the folder.)Tap or click the Home tab, tap or click Easy access, choose Include in library, and then select the library to which you want to add the folder.