I can't see any music when my Sansa c250 is connected.

See my tip posted here, I think it will help.....
Solve your MP3 Player Connection Problem.

Plug it into your computer via the usb cord and bring up the players contents on My Computer>Player and delete the contents within the folders you want, most likely the Music Folder.

how do i add music from my computer to my mp3 sandisk sansa c250 mp3 player

Am not sure which of the 2 actions we did solved the problem...but we installed the CD that came with it (my daughter has a Sansa C260 and her CD was already installed in the computer and we thought I didn't have to install mine). But we resorted on installing mine too in case it would help with the problem, and then we re-loaded all the songs into my Sansa C250 at a slower pace, although I really don't know if the quicker pace did cause the problem. But now my Sansa C250 is now able to record any song correctly.

Delete when connected to your PC using Widows Media Player.

yes i have the same problem how do i get the music onto card itself

Use Windows Media Player instead

Open "My computer", then "Sansa c250 (E:)", find properties to show hidden files and a "Music" file (which is hidden) will appear. You can erase music directly from there.

You can manually delete the music thru My Computer. My Computer>Device Name (c250)>Media>Music You can see all of the music by albums and delete what you want. Please add to this question if you need more assistance. Best of Luck.

That's a pretty weird problem. The only suggestion I can give you is to check to make sure the music you put on was 1) in mp3 or wav format and 2) if this is music you have purchased, to ensure you have the rights properly set to play the music