From: http://wincdemu.sysprogs.org/

WinCDEmu is an open-source CD/DVD/BD emulator - a tool that allows you to mount optical disc mages by simply clicking on them in Windows Explorer. If you have downloaded an ISO image and want to use it without burning it to a blank disc, WinCDEmu is the easiest way to do it.

From: http://www.slysoft.com/en/virtual-clonedrive.html

Virtual CloneDrive works and behaves just like a physical CD/DVD drive, however it exists only virtually. Image files generated with CloneDVD or CloneCD can be mounted onto a virtual drive from your hard-disk or from a network drive and used in the same manner as inserting them into a normal CD/DVD drive.

http://www.poweriso.com/

PowerISO is a powerful CD / DVD / BD image file processing tool, which allows you to open, extract, burn, create, edit, compress, encrypt, split and convert ISO files, and mount ISO files with internal virtual drive. It can process almost all CD / DVD / BD image files including ISO and BIN files. PowerISO provides an all-in-one solution. You can do every thing with your ISO files and disc image files.

http://www.daemon-tools.cc/eng/products/dtLite

Most popular product that offers easy tools for making simple disc image files and emulating virtual CD/DVD drives.

http://www.magiciso.com/tutorials/miso-magicdisc-overview.htm

MagicDisc is freeware. It is very helpful utility designed for creating and managing virtual CD drives and CD/DVD discs. For anyone who deals with CD-based programs

From: http://www.ltr-data.se/opencode.html/#ImDisk

ImDisk is a virtual disk driver for Windows NT/2000/XP/Vista/7/8 or Windows Server 2003/2008/2012. It can create virtual hard disk, floppy or CD/DVD drives using image files or system memory.