Understanding MultiBooting
and Booting Windows from an Extended Partition

by Dan Goodell

Creating an Image of Each OS Installation

Just for the sake of simplicity, we'll initially install each OS in a 2-GB partition and adjust the partition size later. We also want a place to keep the OS backup images, so let's partition the hard disk accordingly. Boot from the boot floppy, then start PartitionMagic. Assuming a 40-GB disk, create a 2-GB FAT32 primary partition at the beginning of the disk, a 20-GB extended primary partition at the end of the disk, and make the rest in the middle a hidden primary partition of any format. The hidden partition is just a placeholder at this time, just to make it easier to repeatedly delete/recreate the 2-GB first partition as we go along. Make sure the 2-GB partition is marked 'active' because that's where we're going to start installing an OS. In the extended partition create two FAT32 logical partitions. The second one is where we'll store our OS backup images as we create them, so make sure it's big enough.

In the discussion below I will refer to these partitions as Pri (primary) or Log (extended logical). Depending on what format we use for the partitions, the drive letters may appear to jump around, which can be confusing. Remember that each OS assigns drive letters at boot time, so it's not really useful to fixate on drive letters for the partitions at this time, anyway. (By the way, the drive letters PartitionMagic shows are just wistful projections--guesses that may or may not be right, depending on what we eventually use the partitions for.)

Reboot from the boot floppy and DOS should designate Pri-1 as C: (2-GB). Install Win98.

After installation is complete, we're ready to make a backup image of the Win98 partition. If we plan to eventually boot Win98 from a partition above the 8-GB barrier, the Win98 boot sector may need to be patched, so we may want to patch the Win9x boot sector now before we make the backup, or we can wait and do it later.

Otherwise, reboot to DOS, run DriveImage, make a backup of Pri-1, store it on Log-2 (probably called E: at this phase). Then use PartitionMagic to delete Pri-1 and recreate it (either FAT32 or NTFS), fresh and ready for Win2000.

Now install Win2000. After installation is finished, repeat the steps to make an image of the Win2000 partition. Note that if Pri-1 was formatted NTFS, DriveImage will not show it having a drive letter, but you can still make an image of it and save it on Log-2 (notice that unless DriveImage shows a C: primary, the former D: and E: will appear to DriveImage as C: and D:). Then, it's back to PartitionMagic to clear/recreate Pri-1 and make it ready for another OS installation.

Reboot and repeat for WinXP (install, make image, and refresh Pri-1), then once more for DOS.

Now we have all our OS images. We're ready to put the pieces together.

author: Dan Goodell, ©2003