Do you know what PTC tool is available to read old .des files made with Pro/Desktop Express 2001 ?
I happen to still have WF3 on my machine and I fired it up and it seems to be able to open *.des files. If you're on maintenance, you should be able to download and install it.
I'm working in WF4 on my current project and it will not, so you need to get WF3.
I'm opening *.des files on 32-bit WF5. 64-bit doesn't work. The features are coming in without the ability to modify them.
This is covered in CS37348