Mounting ISO’s in Vista x32 is not an issue, most of the XP tools would work. In some cases you might have to run them as Admin, but there are not major issues. I have been using the old XP Virtual CD Control Panel from Microsoft which you can find more details on MSDN download section.
However if you are running Vista x64 like I am then that is a little different matter. One option that has worked and I would recommend is getting the Daemon Tools version 4.08 x64 which work absolutely fine. You can download that from here (make sure you select the x64 bits and not the x32).