My Clip keeps overwriting my music

I just bought a Sansa Clip + and was very excited to start loading it with music.  I hooked up with WMP and I can sync music onto it, but it overwrites the music everytime I sync. 

To clarify, I loaded some tracks and then went back to add some more.  The older songs just disappeared when I sync’d the new songs.  Why is it doing this?

Your Windows Media PLayer might be configure to Sync automatically causing the songs loaded already to your player to be overwriten. If you are using WMP 11, click on Sync tab > Sansa Clip > Setup Sync and uncheck “Sync this device automatically”. For WMP 12, just right click on the Sansa on the left pane and select Setup Sync and uncheck “Sync this device automatically”.

First of all, this is the Clip forum. There is a separate forum for the Clip+. If your music is not protected, then I suggest that you set the USB mode on the player to MSC, and use windows explorer to drag and drop or copy and paste the music to the player. If you already have music on the player you put on in mtp mode, you might want to format the player using the player’s menu to delete all the songs on the player, then switch to msc mode and copy them to the player again. Songs transfered in mtp mode won’t be visible on the player on your computer screen when the player is connected in msc mode and vice versa.