HI!, I know many people had posted about this topic, but I couldn't get a steadly answer! my computer has XP pro on first HD, 2000 on second HD, how can I select between the two on the boot up without the help of any software! (suggestions about software would be fine) Thank you so much!!!

You just have to go into bios at start up and go to boot order. select which hardrive to boot to hdd o or hdd 1

Thats one way of doing it. Or you could do a Repair Install of Window XP and that will set up dual boot for you. Or you could use a Boot Manager which will effectively do the first option for you automatically without having to go into the BIOS. Try BootIt NG, the Worlds best boot manager. http://terabyteunlimited.com/ Stuart

thanks for all your helps!

Presumably each OS was installed to its drive independant of the other; i.e. each drive was set as Master drive in turn? Each drive can boot independantly of the other? To achieve what you want - dual-boot option and no software added. Set drives as follows: XP as Master drive, with W2K as Slave. Boot to XP, and access the boot.ini on the W2K drive (it's on the root of W2K Primary partition). Copy the line for W2K in that W2K boot.ini to the boot.ini on the XP drive. Then edit the line (now part of the XP boot.ini) that refers to W2K as follows: Change the entry for rdisk(0) to read rdisk(1) - in the W2K line. Save changes and exit. Reboot and you 'should' now be able to boot to either OS - without any add-in software. Should you ever wish to revert to either drive booting independantly as you may be well be doing now, then you can do so. Both drives are untouched - apart from an extra line/entry for W2K in the XP boot.ini. Your XP boot.ini will resemble: [boot loader] timeout=30 default=multi(0)disk(0)rdisk(1)partition(1)\WINNT [operating systems] multi(0)disk(0)rdisk(1)partition(1)\WINNT="Microsoft Windows 2000 Professional" /fastdetect multi(0)disk(0)rdisk(0)partition(1)\WINXPPRO="Microsoft Windows XP Professional" /fastdetect In the above example the default OS to boot = W2K, not XP as you would probably have at present. The two critical lines are those that point/refer to W2K and XP respectively. For XP, rdisk(0) = XP on the Master drive; partition(1) means that XP is installed in Primray partition on that drive. For W2K, rdisk(1) = W2K on the second/slaved drive; partition(1) means that W2K is installed on the Primary on that slaved-drive. Shouldn't take you more than a few minutes to do the job; longest part resetting the drives as Master/Slave? Either use cable-select, or the 'older' master/slave jumper routine? If using cable-select then the Master goes at the end of the ribbon, Slave in the middle. If using 'older' routine drive position on ribbon-cable doesn't matter. Incidentally you could just use the boot.ini example above as a model to manually create/write the additional entry for W2K in the XP boot.ini; thus there would be no need to copy the actual line from W2K boot.ini to XP boot.ini? BTW: the entry for XP in the above is not the standard winnt - I change/customise each default OS folder name slightly to clearly identify which is what at all times... Probably your XP line will refer to XP as winnt. Finally, each OS will boot as c: etc. Path statements etc. will remain correct for each OS.