In my work, many questions about Windows NT come up over and over again. In this article, I'll answer some of these questions about NT installation issues and NT coexistence with other operating systems.
To get the most from this article, you'll need a basic understanding of active, boot, and system partitions. (For more information on partitions and the boot process, see Mark Minasi, "Troubleshooting NT Boot Failures," April 1997.) In the Master Boot Record (MBR) of each disk, you can mark one partition as the active (primary) partition. When the computer starts, the computer will look at the partition boot record of this partition for information on how to start the operating system. With utilities such as FDISK and Disk Administrator, you can set which partition is the active partition; however, changing the active partition can be dangerous and can result in your computer failing to boot. (For more information on NT's Disk Administrator, see Michael D. Reilly, "Windows NT Disk Administrator," November 1996.)
Boot and system partitions are NT terms that refer to the partitions containing the %SystemRoot% structure (e.g., \winnt) and the core startup files (ntdetect.com, ntldr, and boot.ini), respectively. These two partitions can be the same physical partition, and this configuration is not uncommon or a problem. The system partition must be the active partition.
Q: I have Windows NT installed. How do I install DOS on the same system?
Typically, you format the hard disk, install DOS, and then install NT. The NT installation will detect the existing DOS installation and add it to the startup menu. You don't want to install NT first because you will lose your configurations and setup when you install DOS.
When you install DOS, you replace NT's MBR with DOS's boot files, thus disabling the NT boot menu. But, you can fix this problem with the procedure I outline below and with one condition: The system partition (the active partition) must be FAT because DOS cannot read NTFS.
On the NT machine on which you want to install DOS, make an up-to-date Emergency Repair Disk (ERD). Run the rdisk.exe utility that NT supplies. When the utility starts, select Update Repair Information. When the repair information is updated, click Yes to create the ERD. Keep this disk in a safe place.
Next, ensure you have the three NT installation disks. If you have misplaced them or cannot access them, you can re-create them with winnt32/ox. Load the NT installation CD-ROM, and enter the command
<CD-ROM drive>:\<processor type>\winnt32 /ox
After you've created the three installation disks, store them with the ERD and insert disk 1 of the MS-DOS installation disk set. Reboot the machine. Install DOS. The machine will reboot into DOS and you will notice you've lost the NT boot menu.
Now, insert disk 1 of the NT installation disk set and reboot the machine. The installation routine will prompt you to insert disk 2. After the system has read disk 2, the display will give you several options. Press R for repair. Deselect all options except Inspect Boot Sector and continue.
From here, follow your usual installation process. If you let the NT installation process detect hardware, press Enter and insert disk 3. If you specify drivers, press S and insert the relevant disks. The procedure will ask whether you have an ERD. Select Yes, and insert the ERD. This procedure will replace the MBR. The system will prompt you to remove all disks and reboot the machine. You will see the old NT boot menu, but you won't have a DOS menu item.
When NT has completed the boot process, log on and start a command prompt (cmd.exe) to update the boot.ini file to include an option for DOS. Before you can edit the file, you must remove the read-only and system attributes. Type
attrib c:\boot.ini -r -s
Now edit boot.ini and insert
c:\="MS-DOS"
at the bottom of the file. Set the attributes on boot.ini back to the defaults with
attrib c:\boot.ini +r +s
Reboot the machine. Now you have MS-DOS and NT on the boot loader menu.
Q: I have a new hard disk. How do I move Windows NT to this new disk?
You can accomplish this task in several ways, depending on your setup and needs. If you have a tape drive, here's the best method to use.
Back up your NT disk to a tape, and make sure you back up the Registry (this step is a separate check box in NTBACKUP). Create an up-to-date Emergency Repair Disk (ERD) with the RDISK utility. Make sure you have the three NT installation disks (you can create the installation disks with winnt32 /ox). Shut down NT, and insert the new hard disk in place of the old disk.
Install NT on the new disk in a directory with a different name from your final NT installation directory name (i.e., if you will install to winnt, install this version to winntemp). When you finish the installation, restore your backup tape. Sometimes problems exist with Registry entries, so reboot and boot off the NT installation disks.
After inserting disk 2, select Repair, and select everything except Check System Files. You will need to insert disk 3 and then the ERD. Reboot, and NT will work as required. You can delete the temporary NT installation, but you might find it useful.
If the tape drive is not an option and the partition is NTFS, you can use the scopy utility from the Microsoft Windows NT Resource Kit. Install the new hard disk, create an NTFS partition on it, and perform
scopy <source drive>: <target drive>: /o /a /s
To use scopy, you must have backup and restore user rights. When you complete the copy, shut down NT, remove the old drive, and set the new drive to master (if IDE) or SCSI 0/6 (if SCSI) and boot off the NT installation disks. Again, repair everything except Check System Files. If you have time, create a temporary NT installation on the drive before performing the copy. If you boot off this minimal installation and perform the scopy, you won't have files locked from your real NT installation. If you use a temporary installation, repair the boot sector only. This caveat also applies to the first method. Create the backup while booted into an alternative NT installation to ensure that no files are locked and that you don't compromise the integrity of the backup.
Other methods for moving an NT installation to a different disk include Ghost copy from Ghost Software (http://www.ghostsoft.com) and DriveCopy from PowerQuest (http://www.powerquest.com). These methods copy an entire disk and eliminate the need for performing a repair.
If you are moving NT to a different type of disk (i.e., one that needs a different driver), install the new driver before you perform the copy. When NT boots using the new disk, the required drivers will be available.
Q: How do I remove Windows NT from my system?
If you have no other operating systems installed, you can simply format the system and boot partitions. But, if you also have DOS and Windows 95 installed and you want to keep that operating system, follow this procedure:
Create a DOS bootable disk (format a: /s from a DOS machine), and copy the deltree.exe utility to it. Boot the machine with this disk. If the boot partition is FAT, delete the %systemroot% tree structure. For example, for winnt, type
deltree winnt
If the boot partition is not FAT, you must use fdisk.exe or the delpart.exe utility to remove and re-create the partition.
You'll also find a Program Files directory structure that might contain NT-related programs; however, Win95 might also use this directory. If you are confident another operating system is not using this directory, you can delete the structure with the deltree.exe utility. Or you can delete the NT subdirectory with
cd progra~1
deltree window~1
Now remove the NT boot files, which are at the base of the system partition:
del ntldr.
del boot.ini
del bootsec.dos
del ntbootdd.sys
(Use the last line only if you have SCSI disks.) You must also delete any page files that NT has created. Check the base of each partition for pagefile.sys, and delete any you find:
dir <drive>:\pagefile.sys
del <drive>:\pagefile.sys
Boot your computer with a Win95 or DOS startup disk, and type
sys a: c:
This command will replace the Master Boot Record to look for DOS and Win95 startup files. When you reboot the machine, NT will be gone.