For any given physical drive you can have a primary partition and an extended partition within which you can have multiple logical drives. The Master Drive's primary partition would be named C:\. The logical drives within the extended partition would become D:\; E:\.... . However, if you added a Second Physical drive as a Slave it too could be sectored into a Primary partition and an extended partition. Under MS-Dos, however, this second or slave drive's primary partition would then become D:\ . The logical drives on the Master would then start not with D:\ (as before) but with E:\.
In any case, if your are dual booting one OS should be on the Primary Partition. Any others should be put on their own drives and it is irrelevent if it is logical ones or primary ones.

Quote:
Windows can have up to four Primary Partitions or up to three Primary Partitions and an Extended Partition (with the extended partition containing as many Logical Partitions you want).
Yes, except you are limited to 24 total drive letters including the logical drives in the extended partition (drives C: through drive Z: ).
Quote:
If I am dual booting, must both the OSs be on a Primary Partition, or can I have one or both OSs on a Logical Partition? Basically, must an OS be on a Primary Partition?

Yes, you must boot from a primary partition, so you can configure up to 4 OS's to boot per hard disk. (except in the case of installng multiple Win9x installations to the same partition by renaming the Windows folder, but that approach is really crappy).

When doing your installs, install the "smartest" OS last.

The OS does not have to reside on the primary partition but the boot files MUST.
 
In the case of DOS:
MSDOS.SYS
IO.SYS
COMMAND.COM
 
In the case of NT:
Boot.ini
NTDETECT.COM
NTLDR
 
If you can always install the OS's from oldest to newest. Currently I am multi-booting with 98/NT4/2K/XP
 
Here is my configuration for my OS HD:
 
C: BOOT partition/PAGEFILE 2G FAT16
D: NT4 OS 4G NTFS
E: NT4 APPS 10g NTFS
F: 98SE OS 4G FAT32
G: 98 APPS 10g FAT32
H: 2K OS 4G MTFS
I: 2K APPS 10G MTFS
J: XP OS 4G NTFS
K: XP APPS 10G NTFS

Thanks fellas,
 
I've just completed a fresh re-install of XP on my master HD, and on my slave HD (which I have in a cradle for convenience) I'm going to multiboot 98SE and Win2k (I use XP 95% of the time and will just disable my master HD in bios and boot to the slave HD).
 
Currently completing A+ Certification; reason for this thread.
 
Thanks for the help, especially DosFreak for posting those boot files for the OSs.
 
Dazz

You don't have to disable the master HD in order to boot from the slave. Just edit your boot.ini file to add choices that point to your W2K/W98 installs.

Davros,
 
I'll give it a go, but a little guidance would be helpful. My second HD with the other OSs will be on drive D (slave HD).
 
This is the information contained in my boot.ini file. Could you show me the changes I would need to make to give myself the multiboot options for WinXP,Win2k and 98SE.
 
 
[boot loader]
timeout=30
default=multi(0)disk(0)rdisk(0)partition(1)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional" /fastdetect
 
 
Cheers
 
Dazz

Ok, here we go...
 
Since you want to have Win98 involved, it will have to be on the primary master in order to boot. Normally, you would install Win 98 first, then Win 2000, then Win XP. But you already have XP on it's own drive. Don't worry, this is going to be easy.
 
First, decide what file system you need. Remember, Win98 can only see FAT partitions, and XP/2K can see NTFS and FAT. If XP is already NTFS, remember Win98 won't see it, but that's ok here. Just decide now if you want the 2K partition to be NTFS or FAT.
 
Remove the current primary master (XP drive) and install the new drive intended for 98/2k. Make one FAT32 partition using fdisk and mark it active and format it. Remember not to use the whole drive, leave plenty of space for your 2K partition and any other partitions you may want.
 
Install Windows 98.
 
After install is completely finished, insert W2K disk and reboot.
Start the install, and create your new partition for W2K, choosing FAT32 or NTFS. Remember not to delete the Win98 partition!
 
Install Win2K to the new partition.
 
When you are all done, shut down the comp.
 
Add the XP drive as the primary slave drive.
 
Boot into Win2K.
 
Browse to the root of the Win98 partition (should be C:\)and find the Boot.ini file. You will need to set your folder view options to be able to see it because it is a hidden system file. Rename it to Boot.ini.bak.
 
Make a new Boot.ini and add the following text to it:
[size:9]
[boot loader]
timeout=30
default=multi(0)disk(0)rdisk(1)partition(1)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(1)partition(1)\WINDOWS="Microsoft Windows XP Professional" /fastdetect
multi(0)disk(0)rdisk(0)partition(2)\WINNT="Microsoft Windows 2000 Professional" /fastdetect
C:\ = "Microsoft Windows 98"

 
Now find the file NTLDR. It has no extension. Rename it to NTLDR.BAK.
 
Browse on over to the XP drive, to the root, and copy the NTLDR from there to where the renamed W2K NTLDR was.
 
That's it, reboot! Check to make sure all selections work properly, and if you have trouble, you can always make your XP drive the primary master and boot to it like you did before, because no files were changed on that drive.

Thanks Davros,
 
Much appreciated.
 
Dazz