OK, one at a time.
Formatting only deletes content. It won’t affect the firmware that shows you Music, Settings, etc. It’s stashed away somewhere safe on the Fuze.
About your C250 music the answer is: it depends. Some music files have codes built in that prevent you from copying it further or moving it around. Some don’t. If, for instance, you ripped the files from CDs with Windows Media Player, it might have “protected” them unless you specifically told it not to. I fear that might be the case with your C250.
But if Winamp would play them…hmmm…that’s interesting.
Do you already have copies of the C250 music on your computer? It’s always good to have a backup somewhere in case your player has problems. Otherwise, yes, you can copy the files directly. Just find them on the C250–keep clicking deeper and deeper in various folders until you find them. You might have to try both MTP and MSC mode–your computer can only see one at a time.
I’d suggest just copy-and-pasting the songs onto your computer or a hard drive so you have a backup, but you can also just copy-and-paste them onto the Fuze if you’ve got two USB ports.
Don’t use any music-library software for the moment. You don’t need any.
Put the Fuze in MSC mode (Settings/System Settings/USB Mode), find your files either on the C250 or your computer, and copy-and-paste them onto the Fuze. For starters, you might want to just do one album to experiment with.
If you see a Music folder, you can throw it in there, or you can make your own folder, or you can just throw it onto the driveletter. (Just don’t put it into Photos, Temp or Audiobooks, which are treated differently.) Try to play it after you disconnect.
MSC looks like any other hard drive to your computer. This is a beautiful thing because you don’t need any software as a middleman. You can deal with your music files directly. Music-library software like Winamp, Media Monkey, etc. are useful for things like playlists, ripping CDs, etc., but they are not essential.
Did the music play on the Fuze? If not…then there are some tangles.
We have to figure out what kind of files they are. There are a lot of different kinds of music files, and the Fuze plays most of them. Your Windows is set by default to “Hide extensions of known file types,” and we need to see those extensions go to Help and search for “hide extensions.” Or if you’re in XP, here are some instructions I found.
Now your songs will have an extension like .mp3, .wma, etc. If it’s .wma, right-click on one and see if a box is checked saying it’s “protected.” Let’s hope not, because that means it’s protected from you. Those files do need a middleman, and they prefer to have the Fuze in MTP mode. You’d want to send them over with the Fuze in MTP and Windows Media Player sending them, because it will also send the hidden codes to unlock them.
Mp3 should just play if you cut-and-paste it.
Try an album and let us know what happens.