My Zune 80 won't sync!!

[Emma777]

OK so I bought a "used" Zune 80gb (from a close friend who had never even used it cause she has an ipod, just got it as a gift), reformatted the zune itself and upgraded the firmware, installed the software, and started to sync. After syncing about 20 albums it quit and gave me error message: c00d124d. It tells me to unplug the zune and restart it. Plugging it back in, I get the same error message. If I reformat the Zune I can get it to sync again, but again, only a few albums. I looked up this error and I can't find anywhere that there is a fix for it.
So I said heck with the zune software and tried to use Zalternator to use WMP to sync my zune. Well apparently that doesn't work with the software version I have, version 3.0. I used UnZoone to uninstall the software and downloaded version 2.5, but when I try to install it, it will check for updates and download the new version. If I turn off my internet (so it can't check for updates) it just won't proceed with the installation, and tells me to connect to the internet.
What can I do to get my Zune to sync with ANYTHING??? I don't care if it's the Zune software or WMP or whatever. She got it for Xmas last year and doesn't have any receipts or anything, so I don't know if I can call microsoft? Please please help me, I have no clue what to do from here!!