Your goal in creating a multi-boot system is to have all the operating systems coexist in such a manner that they will be capable of sharing files with each other. Nothing is more frustrating than realizing that you must reboot to retrieve a file, copy it to a floppy, and reboot again to copy it into your other operating system. A little bit of knowledge about file systems can save you many headaches down the road.
Install Apps Separately
This is a really important point. Do not attempt to install two Windows operating systems on the same partition. Just as Microsoft says, you really do need separate partitions for each OS. You should also install all your apps separately for each OS, typically on the same partition as ...