When you say update, do you mean the update to iTunes or the firmware on the iPod?
Your music will not go away unless you physically delete the My Music folder in the My Documents folder.
I'd suggest you uninstall iTunes from Add/Remove. Then, uninstall Quick Time. Now download the latest version of iTunes and install it. It will find the default location of your music which is C:\My Documents\My Music\iTunes and integrate your music.
I've had itunes since 2007 when I first got my ipod nano and anytime there was an update, I'd update with no problems. A few days ago, I tried to do an update and for some reason it won't update for me at all now. And now I've lost my itunes download. I called itunes for some technical support and they couldn't help me get it back.
Has anyone ever had this problem and if so what did you have to do to get the itunes software to download again. I have all kinds of music playlists on my itunes and I want it back. Can someone help me? Thanks for any replies and help with this.