I think that virtualisation is the solution for using the old stuff. I would:
1. Install XP/Win7 in a virtual machine (
Virtualbox for example).
2. Leave the network adapter disconnected so that the virtual machine is disconnected from the internet.
3. Use USB sticks/file sharing to install flash or whatever else is needed.
4. Make images from the S&T DVDs.
5. Mount the ISO image in the virtual machine.
If possible maybe even copy the files from the DVDs to the virtual machine and access them internally from Windows.