From the page:
With Mozilla Firefox for HP Virtual Solutions, the SVS application virtualization technology from Symantec™ further protects your PC by containing Firefox – and everything you do on the Web! – in a “virtual layer”
Basically, it looks like the application is wrapped in a virtual layer, which can be reset to defaults by a menu item. I don’t really understand the point though, since it’s running software AFTER downloading that usually gets you.