Found this in another thread, hope it helps. The whole thread is here. http://www.vguitarforums.com/smf/index.php?topic=1696.0Great news! I figured it was unlikely that Roland was using a one-off chip for MIDI and audio I/O, so I went looking through devices under their Edirol line. I
found the UA-4FX - a USB audio/MIDI interface http://www.rolandus.com/support/downloads_updates/eula.php?FileName=UA_4FX_win_vista_x64.zip
1. Download and install driver for UA-4FX
2. Plug in USB cable for 99
3. Cancel out of driver install wizard
4. Open device properties for VG99 in device manager
5. Click on driver tab, click update driver
6. Select browse
7. Select Let me pick from a list of drivers
8. Select Sound, Video And Game Controllers
9. Select Roland in Manufacturer list
10. Select UA-4FX, click continue on "may not be compatible" warning
And it works! I select UA-4FX for my MIDI IO in the editor and I can work with the 99, and it also worked for audio in Sonar. I've only tested on my machine, so no guarantees. Good Luck!
PS. It's slightly annoying that Roland hasn't taken this simple step for us, the Edirol drivers that work with the USB IO chip in the 99 were released in 2007.