lammert - 2:43 am on Sep 28, 2010 (gmt 0)
It is really surprising that Windows 7 has no built-in support for mounting ISO files. They provided a tool for Windows XP but it doesn't work on Windows 7, at least not on the 64 bit version. You are bound to use some third party tools.
I don't have much personal experience with these tools (I use the VMWare virtual server ISO mounting functionality whenever necessary) but you could try PowerISO, virtualclonedrive from SlySoft or the Daemon Tools.