[Sivran]

Just remember you need to install the older OS -first-. The newer one will detect the old one and start the process of setting up dual-boot for you.

If dual-booting Windows and Linux, always install Windows first. The friendlier distros, such as Red Hat, Mandrake, and SuSE will detect windows, and offer to set up dual booting.

Win 9x/Me can't read NTFS, so they need a FAT32 partition ready for them to use. Linux can read and write to FAT32 quite well, but should be installed to its own partition with its own filesystem anyway.

After that, both operating systems should operate normally.