Ok... since I see many posting asking about how to configure dual boot with Windows, I'll try to make a simple How To here, as far as my experience making multiple boot OSes... For you who'd like to boot to even more than 2 OSes, this might help.

Now... the first time to prepare to be able to do multiple boot OS, is defining partitions, each OS must have its own partition for its system, while sometimes we want to share data between them, it would be better if you also create data partition where you can put all shared data there... To do a partitioning drive, you can use some utilities such as fdisk and Partition Magic from PowerQuest. If you'd like to install more than 1 MS OS in single drive, you'll have to use utilities which can create more than 1 "primary partition", DO NOT USE MS-DOS' FDISK! it will only create 1 primary partition and force you to make additional partitions as logical partitions, you may use Linux's fdisk if you like, but for most people, this utility is confusing, so I recommend using more user friendly disk partitioning utility like Partition Magic. Linux partitions can be placed at logical partition.

Note: For MS OSes, DO NOT create partitions with starting point above 8Gb boundary, if you do, the OS won't boot. Please note that "starting point" means only the beginning of the partition while the rest of it can cross the boundary.

Note: if you define more than 1 primary partition with Partition Magic, it will make only 1 of them is visible, you can use utility like Linux's fdisk or Partition Editor which comes with Partition Magic to change the drive visibility.

Format all of Windows partitions, use FAT32 for Win9x partitions. For shared data partitions, format them using FAT32 too, since FAT32 is supported by many OS.

Note: There is a limitation for primary partition creation, you can only define up to 4 primary partition, this will limit to maximum 4 MS OSes that can be installed to single drive. And you will notice that if you define extended partition, this will make only 3 primary partition left since extended partition need 1 entry at primary partition entry.

So, after deciding your hd layout, then, install all of Windows OS as you wish... If you'd like to install more than 1 MS OS (eg. Win98 and Win2k), then, install one of them first, then before installing the other, HIDE! (this is a must for successfull MS install, otherwise, you may come up with confusing configuration) your finished partition and SHOW the empty partition, then do the second install, and so on...

Linux should be installed last for easier configuration, and for booting to other drive (for those of you that have more than 1 hd) use GRUB as the Linux Loader since GRUB has the feature to map drives, simulating your second hd as the first and swap them. If you only boot to single drive, then you can choose either GRUB or LILO. Install them at MBR! This is the easiest one!

Note: when installing last Linux, configure all of the drive as you will use it everyday. This is needed since only the first drive (Primary Master for IDE drive) MBR will be used.

After installing all of the OSes, now the last thing to do is configure the Linux Loader. for GRUB, you may add lines at /boot/grub/grub.conf like the following:

---
default=0
timeout=10
splashimage=(hd0,5)/boot/grub/splash.xpm.gz
title Windows 2000
rootnoverify (hd0,1)
makeactive
chainloader +1
title Windows 98
rootnoverify (hd0,0)
makeactive
chainloader +1
title Red Hat Linux 9
root (hd0,5)
kernel /boot/vmlinuz-2.4.20-8NTFS ro root=LABEL=/ hdc=ide-scsi
initrd /boot/initrd-2.4.20-8.img
---

while for booting from other drives, you can use map command for MS OSes, this is not needed for Linux. Here's an example for booting Win2k from second drive:

---
title Windows 2000
rootnoverify (hd1,0)
map (hd1) (hd0)
map (hd0) (hd1)
makeactive
chainloader +1
---

while for lilo configuration (placed at /etc/lilo.conf):

---
prompt
timeout=50
default=linux
boot=/dev/hda
map=/boot/map
install=/boot/boot.b
message=/boot/message
linear

image=/boot/vmlinuz-2.4.20-8
label=Linux Red Hat 9
initrd=/boot/initrd-2.4.20-8.img
read-only
append="hdc=ide-scsi root=LABEL=/"

other=/dev/hda1
label=Windows 98
---

Note: after changing lilo.conf, type lilo at the shell prompt to activate the changes. For GRUB user, no activation required, GRUB will read the configuration at boot time.

IMPORTANT FOR WIN2K USERS:
Win2k users will likely to experience slow booting after installing Linux, this because Windows is trying to assign drive letters to Linux partitions while they can't be read by Windows (filesystem not supported). To avoid this, before installing any Linux, remove any drive letter assignments for Linux partitions at Drive Manager.

Ok... hopefully this will help a lot of users who'd like to make multiple boot OSes...

thanks for these excellent infomation

danny - how about using lilo with 2 hard drives? I have win ME installed on a 60 gig hard drive (partioned for 50 and 10 gig windows partitions)

I then installed mandrake 8.1 onto an 8 gig hard drive - I can access the linux drive via a boot disk made during setup or I can boot into windows - but when I use lilo to boot I get to the part lilo is about to start and I get LI and nothing more - stops DEAD.

I'm not sure how to show my lilo.config I see posted in here as I am a total newbie to linux.

Any help would be greatly appreciated, as floppies fail and the boot process is SLOWWWWWWWWW via the disk.

I'm afraid a can't help much with LILO, now I'm using GRUB for my boot loader since GRUB can boot from other drive with map command. I don't know if LILO has similiar command or any way to be able to boot from other drive, may be someone can tell me how? I'm curious about "disk" command at LILO...

For now, I can only suggest you to use GRUB instead of LILO...

well after Numerous tries using lilo with no sucess I thought I'd try with grub. I wasn't sure of the simple text based interface - but hey guess what it works GREAT! I think the problem may actually be due to the graphical nature of lilo. My video card is an Nvidia and my mandrake linux had a hard time with it during the install. Oh well I got grub working (and was even able to edit the menu to reset the default HD) so I'm happy.

Thanks for any or all that helped.