Here's what i did. Same as above but I found this quicker.
1. Open the desktop app
2. Open Windows Explorer
3. Insert your SD card and navigate to it in Windows Explorer
4. Make a folder for each of these on the SD card (you only need to make the folders you want to add to the library):
Music
Video
Pictures
Documents
5. On the C Drive create a folder called SD
6. Right click on My Computer and click Manage
7. Click on Disk Management
8. Find your SD card volume, right click on it and click Change Drive Letters and path
9. Click add and then click browse
10. Navigate to the C:\SD folder you created and click ok and ok again
11. Close Computer Management
Your SD card will now be mounted in the C:\SD folder you created. You will now have a C:\SD\Music folder, C:\SD\Pictures folder,C:\SD\Video folder and a C:\SD\Documents folder. Windows will now see that SD card as a local drive. You can now add those folders to the media library.
To add to the media library:
1. Open the desktop app
2. Open Windows Explorer
3. Navigate to a library such as pictures.
4. In the ribbon at the top click Manage under the purple Library Tools.
5. Click Manage Library
6. Click add, Navigate to your folder (C:\SD\Music for example) and click Include Folder
7. Click OK to close the library management for that library and move on to the next library if needed.
I hope this helps. I keep saying click when I mean tap. Kinda hard to let go of that ole mouse......