Hi there, don't know if this will help or not. To delete files in WMP 10 just right click it and you have the option of deleting it from the library only or the library and the computer. i choose the first one unless I want to get rid completly. As for adding files to the library I go to FILE / ADD TO LIBRARY / BY SEARCHING COMPUTER then choose where I want to add the files from by finding the folder the files I want to add are in.
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