Virtual CD/DVD drive

Every time when I download ISO image from MSDN I burn in to CD/DVD to Install software. I just wonder is there any virtual CD/DVD drive, which can save our CD/DVD cost as well out time. My colleague David Yeo told me that there is software called DAEMON Tools. Visited the website and downloaded the software… Wow…. What a wonderful tool which meet my requirement the tool can offer following things :

DAEMON Tools is an advanced application for CD/DVD discs emulation. This program allows running Backup Copies of your CD/DVD images.

DAEMON Tools needs a 1:1 Copy to run!!
DAEMON Tools is used to run CD/DVD backup images
Generic DVD-ROM is able to run nearly every CD/DVD image like it was the original CD/DVD! Just do an image file using one of the supported burning programs and mount it with DAEMON Manager

Cost : Free