7.x Reader (I don't have the full version) generally works very well for me on Win2k. There have been some updates - maybe try to snag the latest version - I've got 7.0.2 here.
[link|http://www.adobe.com/products/acrobat/readstep2.html|Here] is the beginning of the download links.
Otherwise, I don't know what to suggest. HTH. Luck!
Cheers,
Scott.