It seems that you suggestion to load Vist64Bit drivers via the "device update" is a dead end, as Roland products are notorious unwilling to install while the product is connected to the USD port of a computer.
On the following web site Roland has published a list of products for which there are WIN 7 drivers available, as both the SC-8020 and XV-5050 (which are the sound modules I am interested in) are not mentioned, I deduct that there are (as yet) no WIN 7 drivers available.http://www.roland.com/support/article/?q=information&id=62223370#audioif
If someone knows of any outside suppliers please let me know. It would probably not hurt if all with the same (or similar) interest would contact Roland/Edirol asking them to provide WIN 7 drivers ASAP.
Presently there are hardly any sound modules available with MIDI out or through, which I need for outputting chords to my Voice Works.