I lost my disc can i still download

You can put music on it by doing the following (assuming vista/XP environment):

Connect it to your PC using the provided USB cable.
Open windows explorer and navigate to your Sansa Clip.
Click through "sansa clip", "internal memory" to the "music" directory.
Drag and drop MP3/wav files to this directory. Feel free to create subdirectories.
Your music will be accessible after doing this.
Be aware that the clip ignores your directories. It will look for artist, album, and title tags to categorize your tracks. You may have to look for your tracks in the "unknown" album directory when playing if your tracks don't have these (ID3?) tags.

Good Luck!
JakeE333