I did this without problems
I was able to get Win7, Win2K and XP networked and running happily though I recently tore my Win2k system down. Win2k doesn't use XPs default "simple file sharing" so it's just as if you've unchecked that box. I have found more success using "the" administrator rather than "an" administrator account, however. I don't see why you cannot set up a folder in the 2K box, share it and move any and all desired files and folders there. As long as your Win7 box has the same username/password account, it should work. There's one small glitch I ran into along the way having to do with Windows SMB that needed a policy tweak but I've forgotten exactly why it was needed. Anyway, all worked fine for me. Link below. Good luck.