You don't have a choice in the matter. NT defaults to 2 options on a CLEAN boot (ie, reformatting the drive during setup). When you install over an existing operating system, it includes the existing operation system on the boot menu automatically. If not, there's an entry in the knowledge base on adding the MS-DOS boot and the Win98SE boot to the menu. It's not hard. Just make sure that you READ the screens before pressing any key. I remember the first couple times I installed it, I wasn't paying attention and it exploded in my face (one time almost literally, but that was the power surge that blew the power supply and almost all of the internal components) and I had to reinstall. Not too bad, since they were clean installs, but that could be disastrous at worst, time consuming at best when upgrading over a previous OS. One word of advice, BE CAREFUL!!! HTH, John