The major advantage of Linux is that it can run directly from CDs. On the other hand, Windows needed to install on to hard disk first. This advantages makes Linux superior when you don not want to install dual operating system and wanted the facilities of both. Thus you can run Linux by CDs on your Windows operating system. Though it is not true for every distribution of Linux, but some version of Linux runs directly from CDs. Generally Linux also run from hard disk like windows, but some of the distributions like Knoppix, Gnoppix, SuSE (called Live-Eval), Linspire (formerly Lindows) and Slackware runs directly from the CDs.