1. To add media files to your Windows Media Player library, select the file(s) you would like to add and then right-click. Select "Add to Windows Media Player list". The files should then appear in your Windows Media Player playlist.

2. Alternatively, you can try the following to add files: Open Windows Media Player. Locate the file(s) you would like to add to your library. Select the file(s) then hold the left-button down to drag them to the area denoted below.

If you have additional questions about how to add files to your Windows Media Player library, please visit the Windows Media Player knowledge base here.