Hopefully this will be helpful for someone else:
NetEdit3 doesn't seem to be compatible with Windows XP Pro 64-Bit. Every time I ran the program and selected the [IPX] or [TCP/IP] buttons, the program would crash. I have other programming software that doesn't work on XPx64, so I have to run these programs in a Virtual Machine running Windows XP Pro 32-bit. I installed NetEdit3 on the 32-bit Virtual Machine and it worked properly.
Chalk another one up to the joys of having a 64-bit computer!