DAEMON Tools
There are plenty of reasons you might want to boot a CD or DVD image from your hard drive rather than having to load the CD each time you use an application. If you have multiple licenses for a software application, it's more convenient to access the disk across your home network via a image on a networked hard drive than it is to dig through a stack of CDs until you find the right one. Two common uses for this type of application are to launch games that require you to keep the game CD inserted in your tray while playing or to create a virtual library of DVDs so you can access them from your hard drive. While the game and movie companies would prefer you not do this, because they assume that all imaging of their products results in theft, there are plenty of times when you are better off leaving the disk at home and taking an image with you. For instance, if you want to watch several movies on your laptop while traveling, bringing all the DVDs and their protective cases wastes precious carry-on space. An image on your hard drive takes up virtual space, but you don't have to worry about scratching the image, leaving it behind in a hotel room or having it ripped off by someone from the hotel staff. As the software EULA clearly states: This program is NOT freeware. If you don't use this program for commercial purposes you do not have to register a license and are allowed to use this software for free. That means free for personal use, but if you want a network CD emulation tool for corporate purposes, you'll need to get a license. Of course, you also need a CD/DVD burning tool capable of creating image files, like Nero, CDBurnerXP Pro, Easy CD Creator or one of the numerous other alternatives. UPDATE: Recent versions of DAEMON Tools attempt to install the WhenU Toolbar following installation of the app. [Windows 9x/2k/XP $0.00]