Copy music files from your computer to the Samsung Focus smartphone using the Zune software. Unfortunately, there is currently no way to mount the drive on Windows Phone 7 devices like you can with many popular smartphone. You’ll have to manage with these steps.
1. Download and install the Zune software. Usually, your music files will be imported to the software automatically. If they aren’t, you can add items under Settings > Collection.
2. Connect your Focus to the computer using the included USB cable.
3. From the main screen, click Collection, then select Music, Videos or Pictures as desired.
4. Select items you would like to copy, then drag them to the Device icon in the lower-left corner of the screen. Use the CTRL while clicking multiple items to copy more than one. Below we copied two songs from the collection.
Any item you drag to the Device icon will sync to the phone.
Note: If any music that is protected with DRM is copied, it will not show up on the Samsung Focus. iTunes music files used to have DRM protection on them, so older files may not work.