Click the "Start" button, and type "Windows Media Player" into the Search box. Click the program's icon to launch it.
Add the MP3 you want to re-tag if it's not already in the Media Player Library. Click "File," then "Open." Navigate to the MP3, and double-click it to add it to Windows Media Player.
Click on the "Library" button, then double-click on "Music." Double-click on "All Music."
Scroll to the MP3 you want to tag. Right-click on the first line next to the MP3's cover art in the "Album" column. If the MP3 album has no name, Windows Media Player sets this line to "Unknown Album."
Click on "Edit." Type an album name for the MP3. Press "Enter" to set it.