Dual or Multi Boot OS

If you want a system with more than one OS on one disk, then there are some rules that must be obeyed.
1. The order of installation: Windows 95, Windows 98, Windows ME, Windows NT, Windows 2000, Windows XP,Windows Vista, Windows 7.
2. You need to install any OS into a different partition. If some of the OS installed on one partition, it would be no problem. For example, Internet Explorer will display an error with the message "iexplore caused an Invalid Page Fault in module kernel32.dll".
3. You can order the computer to start booting all versions of Windows. But you can not boot, if that is used is a combination of Windows 95/98/ME.
In practice this multi-OS, is not providing excess performance. Multi OS performed only if a software can work well in a particular OS.