I am on Windows XP SP3.
Here is a support article from the Digidesign website on how to delete Pro Tools' preferences and databases in Vista:
http://www.digidesign.com/index.cfm?...0&itemid=29201
Also... intitially, after I installed OS 2.7, my Virus TI plug-in would not show up. Only the Virus TI Snow plug-in and of course, I couldn't use that. I emailed Access about this and it kind of baffled them. They suggested pulling the Virus TI Snow plug-in files and this fixed my problem. I just moved the 2 files to the "Plug-Ins (Unused)" folder and now the regular Virus TI plug-in works fine.