Zen Vision: M no longer recognized

I think it was after I installed Service Pack 3...my Creative Labs Zen
Vision M is not recognized by my laptop anymore.

It still works on my XP computer at work (but Creative doesn't have
software for XP anymore; I can only interact with my Zen as a hard
drive, basically)

I have upgraded all of the software offered by Creative for Vista and
followed many, many recommendations for cleaning, rebuilding, and so

The one thing I -can't- do is upgrade the firmware because my computer
claims that my Zen isn't connected whenever I try to do so. According
to one forum, the problem lies with Windows Media Player 11 (but my
laptop has worked just fine for 2 years). Even the online WMP 11 readme
file suggests uninstalling WMP 11, ugrading my firmware, then
reinstalling WMP 11.

HA HA HA, I said. I can't uninstall WMP 11 on Vista!

The only other suggestion from the Creative Labs site is to reformat my
Zen, losing everything. But...I don't think this guarantees that my
laptop will suddenly recognize my Zen again.

Now, because I can at -least- put music on my player from my work
computer, I'm afraid to do a reformat--it's possible it wouldn't work at
all after that...

Any suggestions? Has anyone fixed a similar problem or had the
reformatting go smoothly? I just want to be able to mess with playlists
and add Amazon videos--is that too much to ask?