I recently used the Updater application to update to Sumatra 1.7, but now it won't launch at work where they still have Windows 2000. (My work organization is a bit slow, but they're getting there, finally.)
I checked the main page of Sumatra Portable for O/s compatibility. As of 2011-08-12 @ 0759EST, it listed Windows 2000 as being compatible. I then checked the forums and support pages here and didn't find anything. So I checked the Sumatra Download page, it doesn't list Windows 2000 as one of the O/s for Sumatra 1.7.
If this post is in the wrong place I apologize.