I would recommend taking one step at a atime. Go from one operating system level to another, until your NW is at least NW 5.1. Then bring up the DS to 8.62, making sure to perform the upgrade as closely to Best Practices as possible. Now you can bring up the Windows 2000 AS (good recommendation provogeek)into the Tree. From there, upgrade your GW in place on the Netware box, and then move it to the final home on the Windows 2000 AS.
If you never separate your OS or your DS by more than one major revision, you stay away from lots of problems.
Sean