blackberry problem

[dianew]

i have just had my blackberry unlocked, all my photos and music have disappeared, when i connected it to the computer toget them back a message came on the phone saying a media card with errors was inserted and to do a disc error checking utility on a computer. i don't know what that means or how to do it
if anyone can help i would be really grateful as i use my phone to listen to music more than anything else