I let a friend borrow my mp3 player, when he got it back to me, it wouldn't work. He told me the battery died, so I believed him. I got home from school, hooked it up to my windows vista PC, to let it charge. When I hook it up, it usually gets blue screen to show its chraging, but this time it didn't.I decided it was maybe cuze the battery died completely, since that never happened before to me. After a while, I unhooked it to try to see if it worked, but it wouldent turn on. I tried opening up on the PC, but it came up with :"please insert disk into driver :F" I guess driver F is my mp3 player, I tried resseting it but it didtn work. The PC still recognizes a usb driver being hooked up onto it, but it can't open it. It is a 4gb mp3, I think mp4 acutaly, player. It can show videos pictured & ebooks ontop of music. It forgot the name of the company, but it has a x in a semicirle as a logo. If you can help please do, I don't wann aheve 2 buy another one >.<

The battery may well be completely flat, that being the case it's advisable to leave it on charge overnight,

If this doesn't work then your "friend" has clearly broken it and should replace it for you..

There are many reasons for such an electronic instruments to stop working..
May be the battery is totally drained off
And how do you charge that player.. I mean does it have in build usb slot for charging? Or you use external cable to connect it to PC
Bcoz there may be a problem in the charging slot in your mp3 player...
But as you mentioned that your PC recognizes it ,there is no problem with usb connection

I charge it by hooking it up to the computer through a usb connector. It uses the same connector as a PS3 controler(weird but useful). Anyway, I left it hooked up to the PC since I posted the original question, tried three different cables, and nothing. I made a YouTube video that shows the player & what happens when I hook it up to the PC. Maybe it can help solve my problem.

It just sounds like it's broken... perhaps your friend dropped it. Either way, your friend owes you a new one as it worked when you gave it to him and didn't work when you got it back.