I have a laptop with NT installed. I used partition magic to make the NTFS partition smaller and then converted the unallocated space to FAT32 to install 98. I set the second partion as active then booted off the 98 CD, but when I try to run the setup, it says there's is a non-MS- DOS partition and it has to erase and reformat the whole harddrive. Is there anyway to make it install on the FAT32 partition and leave the rest alone.

Ummm...

You 'had' NT/ntfs and created a second "primary"(?) as fat32, and want to install '98? Presumably this is the second partition on the drive...

Without the use of an add-in util there is no way...

There are a couple of rather tedious options you 'could try' (lot of time/effort...) but probably the easiest approach - since you already have PM - is to use PM's in-built Boot-Magic util to allow to have a dual-boot (of sorts).

The Boot-Magic (boot-manager) util will allow numerous OS installations - 'usually' each in its own Primary - without regard to the basic M$ requirement for a dual/multi-boot; i.e. a common accessed system (C: Active Primary) partition (which is where all installed M$ OS put their respective boot/start-up-files, with each OS itself - its system files - in its own logical-drive). The util allows you to choose which Primary to boot and thus which OS.

Have a read of the PM manual, it should all be in there? Probably you will install PM into NT, and go on from there?

If you go this route - then remember that the inactive OS will be hidden from the active. So to share data you will need (to create) a common accessed fat16 data area - in the Extended partition. NT cannot see fat32/'98 cannot see ntfs - without you use utils from sysinternals.com to allow each OS to see the other's 'preferred' file format.

IF... you were willing to start afresh (after backing up data etc.) then have a read of #3279 on this NT forum; it gives a good way to establish the standard dual-boot ('98/NT). It works - credit to the chap who posted it while back.

And a further explanation (courtesy of John Savill):

http://www.windows2000faq.com/Articles/Index.cfm?ArticleID=13882

You can even boot up with 98 startdisk if you have create a fat partion in NT.when you booting up with win98 startdisk you can install a second system to the fat partion.
when you need acess win you need the win98 startdisk and write at the prompt "win" NT read disks as by number and fat use the alfa numbers. its a alternativ to bootmagic, If you have a encrypt disk there isnt possible to use multiboot, the system vill crash for you. Make a ghost before you make any changes on your hard drive.