1. Create the folder you want to link. I just created a folder named "Shared" in C:\Users\Public\Documents. Everyone already has access to this folder, but it's not super easy to find.
2. Open the command prompt as administrator. (find "cmd" and right-click then click run as admin, you'll see administrator in the window title)
3. Run this command to create the link:
"mklink /J C:\Users\Public\Desktop\Shared C:\Users\Public\Documents\Shared"