1. Are you using Windows Media Player 11 ?
2. Can you see the Sansa e250 connected in the sync mode ?
If no: install and update WMP11
3. Make "new playlist" in the <Library> or <Sync> mode
of WMP 11; screen left side.
3.1 Save "new playlist" in WMP11; screen right side.
4. Put in <Sync> mode your playlist under the player: The player
should be connected showing in WMP11. Start synchronizing.
Leave the player connected until <Sync> is ready.
Support for Sansa e250: