I read recently that the latest version of DAEMON tools contains spyware. So here is a "simple" tool from Microsoft to mount your ISOs from the MSDN Library.
From MSDN FAQ
Mounting ISO files virtually
The following tool for Windows XP allows image files to be mounted virtually as CD-ROM devices. This tool is provided here for your convenience, and is unsupported by Microsoft Product Support Services.
Download Virtual CD-ROM Control Panel for Windows XP