Can we have a dual boot machine with NT and 2000 on a machine? A've already Nt installed on my machine. I tried to Boot from CD ROM using Win2000Pro CD. But after displaying following messages, when I press enter key, it restarts the machine. Booting from CD ROM Press any key to Boot from CD.... Any one can help me?

You need to create a 2nd partition, then during the installation of 2000 you will need to specify that this is where 2000 is installed.

Windows 2000 is NT (version 5)

in order to dual boot between win Nt and win 2000 , you have install win Nt and then deploy service pack 4 install, then u have install win 2000 at any manner.

It can be done, but with some caveats (warnings) which should be recognised/understood in advance. Before you start, perhaps have read of the info at: http://www.winnetmag.com/Articles/Index.cfm?Action=USPrint&IssueID=396 specifically: http://www.winnetmag.com/Articles/Index.cfm?ArticleID=8851 http://www.winnetmag.com/Articles/Index.cfm?ArticleID=8824 which detail how W2K integrates with NT. Things to know include that you must have SP4 or later installed in NT prior to adding in W2K (be it an Upgrade or a dual-boot) - essential if you have ntfs(4) areas already present, or intend ntfs(5) areas later... NT4 cannot seee/handle ntfs5 (W2K uses ntfs5 not ntfs4). When W2K goes in it takes over/replaces the NT mbr with its (W2K) version; it also converts any ntfs4 it finds to ntfs5. This is a compulsory conversion - no arguments/quibbles/discussions about it - a bit like some (over-zealous) religious or political etc. fundamentalists? If no SP4 or later present in NT4 prior to conversion, then NT4 is 'excommunicated' from (denied contact with) any ntfs(5) areas; even those that 'were' ntfs4... Also check the later updated info at: http://www.winnetmag.com/Articles/Index.cfm?Action=USPrint&IssueID=439 Prior to installing W2K, run the chkupgrd.exe util (usually on the W2K CD). It will generate a report indicating what is/ins't OK for W2K on the PC. Ensure you have all required updates, bios, Mobo, VGA etc. - before you start installing W2K. Also W2K is notoriously picky about RAM quality and specs.; and it likes to have at least 128Meg.... You can install via the 4 setup floppies; make these using the makeboot util (also on the CD). This route may circumvent the problem you are (currently) having using a CD boot for W2K install? Possibly W2K CD doesn't like your CDROM (drivers...?). If your present C: partition = ntfs(4) then it 'will' be converted to ntfs5 from its present ntfs4 by W2K; and this may prevent NT4 from booting, once you have installed W2K. I'm not totally clear about this little bit - the inference from M$ and a few other resources seems to be that if the system partition (where all boot/startup files usually reside) is other than fat16 (which NT/W2K/XP can all handle, upto 4Gig...) in a dual-boot with W2K or XP then NT4 will not boot, i.e. if it has become ntfs5 then NT4 cannot see it... NT requires SP4 or later to read/access (with some limitations) ntfs5 - as indicated in linked articles above... Logically this is not present in NT4 until the OS actually boots up... If your C: = fat16 then all 'should' be OK. Also remember that - M$ strongly advise that W2K go into its own partition. Even M$ seem to favour using an add-in boot-manger util... (pigs may one day fly - monkies, dogs, and insects have?). And there is of course the VMWare approach which installs via a host OS (NT4/W2K/Linux and now XP) and allows numerous other OS's to exist in "virtual PC's..." with many useful fringe benefits; but it isn't cheap! VMWare.com is their web-site; perhaps check out. Providing you have everything OK for the install, it would be also useful/wise to checkout the M$ link below... It details with how you get back to an NT4 only system from a dual-boot with W2K (should you wish to)...; and has some useful info too. http://support.microsoft.com/directory/article.asp?ID=KB;EN-US;Q257754 It may well be that it all goes well for you; but then again an add-in util may be easier - considering M$ info.? Add-in boot-utils are (usually) cheaper than VMWare... System Commander handles all flavours of M$ OS and seems to be gaining an edge over PM; PM7x is W2K compliant. Perhaps check out both and some of the freebies around too? Post back with how you go about it? My own preference in dual/multi-boots is (whenever posiible) to go the text book route: small C: fat16 system (active Primary) partition (around 250Meg) for boot-files only. Each OS in its own logical-drive in the Extended partition; shared data logical-drives. NT can be fat16 or ntfs5 (ultimately...); and W2K can also be fat16/fat32/ntfs5. For NT to access fat32 you would need the Sysinternals.com util that allows NT to access fat32. Install NT + SP4 or later first, then add W2K. Make ERD once all is in OK.