Several people have reported having to load these drivers for Windows 10:
MTH Proto-Sound 2.0 and Technology Welcome
If this link doesn't work, they are the last entry on the MTH DCS Protosound page.
Also, I had a serial to usb cable a while back that caused errors as soon as the file transfer started. I had a Rev L TIU and finally found my proper USB cable and then everything worked perfectly. This was with v5 of the loader, but I was using Windows 7 at the time. I haven't yet tried the DCS loader with Win 10, but that is coming soon.