How do you dual boot?

It depends on what your OSes are. The basic rule is have a separate partition for each OS. Install the oldest OS first and the newest OS last. If you are dual booting with Linux, install Linux last.

During my college days and the wonder years of Red Hat Linux, I used to have a system that had three OS namely Win 95, Linux and OS/2 Warp. After umpteem amount of crashes, re-installations, I reduced it to dual boot of Linux and Win 95. But, once I hit a job, I made a concious decision that the computer at home is only for gaming purposes and for fun. So I switched over to Win XP. So that is the current status of my system. Cheers! Ram

This depend on the OS but for windows you should have at least 3 partition, two for different OS and the other you data drive. Install say WinXP on the first boot, then install the second OS say Vista in partion 2. Now move the 'My document' folder to the third partition. This way if one OS has a problem you could still boot the other and your document are all intact. At boot up you will be prompted in DOS mode which OS would you like to boot and that's it.