Mount ISO on Vista RTM
If you're like me, we keep a lot of our stuff (backups, movies, install disks) in a DVD/CD image format (ISO), here's a great way of mounting ISO images on Vista RTM and it's FREE.

(I'm running Vista RTM and mounting a Vista RTM ISO image file. Hope I don't confuse you)
They have builds for Windows 9x/Me/2000/XP/2003/Vista and x64 editions.
There were some reports that it worked on Builds 5536 and some RC1s but many were having issues with getting it to work. I've just tried it on an RTM build of Vista and it worked "magically".
you can download MagicISO Virtual CD/DVD-ROM here.
Need a tool to make ISO images from CD/DVDs? here's a simple one from Scott Hanselman's blog: http://www.hanselman.com/blog/FreeISODiskImageBurningUtilityThatWorksOnVista.aspx
*UPDATE: Daemon Tools already has a Virtual CD/DVD rom tool that works on Vista too, and touted to be able to emulate all known copy protections on the market today. Try it out here: http://www.daemon-tools.cc/dtcc/download.php?mode=ViewCategory&catid=5
Let me know which utility you like better.