worked fine for me.
I just gave my 1st gen iPod to my girlfriend, who is a windows user. We'll forgive her for that since she bought me a 3rd gen iPod for Christmas (hence me giving her my old one).
It was formatted for a mac (my iBook) and we had to get it working on Windows. Basically all we had to do (this was on XP) was:
Plug it in.
Go to My Computer, browse to the new "Removable Device" which will have just showed up.
Try double-clicking on it.
It will then tell you that you need to format it before Windows can use it. So format it.
After this, it will be a blank iPod with no software, so you need to download the Windows iPod software from the Apple site (7mb download). Make sure you choose the right version - there is a version 1.3 or something, for the mechanical scrollwheel iPods (1st gen) and a 2-point-somethingorother for the newer touchwheel iPods.
Install the software, then run it to install the software on the iPod.
Tadaaa, Windows iPod.