Install Windows 98 first. Upon installation, Windows XP will prepare a boot menu with two entries: one for 98 and one for itself.

I use this way (NTLDR + Win98's bootsect), each OS thinks it's installed on drive C:.

Indeed it's easier to first install Win9x, then XP. Because XP recognizes Win9x automatically, but not the other way around. Win98 will probably trash the XP boot sector.
If you don't want to wipe the existing install, there are ways to fix / work around it. I've documented some of them here.
ott's suggestion has its own advantages, I would try that first, if you already have WinXP installed.

I did just that not long ago on a laptop.
I used this tool to reduce the size of the XP partition after defragmenting it. It was freely downloadable from https://web.archive.org/web/20160310034551/ht … m/download.html

And it's mirrored at https://archive.org/details/minitool_partitio … ee_edition_v9.1

Installed Win98se, then you have the choice of installing BeOS Personal Edition under Win98 (if your hardware is supported) and install bootman (the BeOS bootmenu) from the Terminal.
Or boot from a Haiku livecd and install its bootmenu.
It will show one entry per partition and will works flawlessly.

If I wanted to install Win98SE first, how would I format the existing WinXP installation?

I used to be able to do this stuff but it’s been so many years…

The Windows XP partition can be formatted from a Windows 98 boot disk. Navigate to the installation medium and run "extract ebd.cab format.com"; this will make the format command accessible. Formatting the partition from a later Windows installation medium is also an option.

GemCookie wrote on 2025-07-13, 15:13:

Formatting the partition from a later Windows installation medium is also an option.

Would you say it’s easier from WinXP’s disk?

AndreaColombo86 wrote on 2025-07-13, 17:54:

Would you say it’s easier from WinXP’s disk?

The Windows XP installer is more likely to allow a quick format.

First things first what are the system specs? Are you sure the hardware supports Win98?

Second WinXP still has EAX support (It's the last OS that does) so if thats your main reason for the downgrade then no need!

If you want to install both just for nostalgia then that's perfectly valid reason.
Personally I work on the theory prepare the system with the earliest OS and your guaranteed full compatibility.

So in this case, I'd use Fdisk to partition the drive. Typically I go with
4GB Fat32 Primary partition for Win98 (C:\)
Extended Partition
Large Fat32 Logical partition for games and data (D:\)
10GB NTFS Logical partition for WinXP (E:\)

This will mean your drive letters remain the same no matter which OS you boot into (E: will just disappear when in Win98)
It also means if you need to reinstall all your data is safe in its own drive.

I would finally say it may be worth getting a second hard drive to test with. leaving your currant hard drive safe in case everything screws up

Thank you, chinny22.

I’m currently considering two different retro machines. One has a P4 2000mhz, 512Mb RAM, a GeForce 4 MX460 and an Audigy 2 ZS sound card. From what I could gather online, all hardware here has drivers for Windows 98.

The second machine is a P4 3000mhz, 1Gb RAM, a Radeon X550XT, and no sound card (I would buy one separately). I believe this should also work with Windows 98.

The EAX thing is a bit particular, as it has to do with specifically with the occlusion effect in Baldur’s Gate 2. It turns out it doesn’t work on Audigy sound cards with WDM drivers, so if I run one of those, I need VxD drivers to get occlusion—hence the need for Windows 98.

From what I read in another thread here on VOGONS, older Creative sound cards like the SB Live! still provide the occlusion effect with WDM drivers, so I’m now deciding whether to go with an older card and keep Windows XP, or get a newer one and dual-boot Windows 98.

AndreaColombo86 wrote on 2025-07-14, 10:57:

Thank you, chinny22. […]
Show full quote

Thank you, chinny22.

I’m currently considering two different retro machines. One has a P4 2000mhz, 512Mb RAM, a GeForce 4 MX460 and an Audigy 2 ZS sound card. From what I could gather online, all hardware here has drivers for Windows 98.

The second machine is a P4 3000mhz, 1Gb RAM, a Radeon X550XT, and no sound card (I would buy one separately). I believe this should also work with Windows 98.

The EAX thing is a bit particular, as it has to do with specifically with the occlusion effect in Baldur’s Gate 2. It turns out it doesn’t work on Audigy sound cards with WDM drivers, so if I run one of those, I need VxD drivers to get occlusion—hence the need for Windows 98.

From what I read in another thread here on VOGONS, older Creative sound cards like the SB Live! still provide the occlusion effect with WDM drivers, so I’m now deciding whether to go with an older card and keep Windows XP, or get a newer one and dual-boot Windows 98.

For the Win98 side of things CPU doesn't really matter. Win98 can't take advantage of Hyper Threading, but this doesn't really matter as the CPU itself is still crazy fast for WIn98 and it'll just "ignore" the HT.
For WinXP the faster the CPU the better. It's a cheap easy upgrade.

More Important is what chipset the motherboard uses, most P4 era do support Win98 but some are better then others with Intel 8x5 being a safe bet. eg 845, 865

GF4 MX is a very compatible card for Win98 side of things but underpowered for WinXP (but then so is any card with Win98 support)
The Radeon is more powerful which will benefit XP but drivers aren't as stable.

Audigy 1 and 2 still support VxD drivers, Although Audigy 2 by default installs WDM. Joseph Joestar did a very good guide on how to do a clean install of VxD
Guide: Installing Windows 9x and DOS drivers on Audigy cards (version 3.1)

I'm not familiar with the Baldur’s Gate issue so not sure if it just requires VxD or specifically a SBLive!
I'll admit I don't really notice any difference in sound quality between a Live and Audigy 2.
The main benefit is the Audigy will give you EAX 4 support if any of your games use it.
https://www.vogonswiki.com/index.php/List_of_ … ith_EAX_support

Thanks again.

The P4 3000Mhz, which is the machine I’m keen on, has a Gigabyte 8TRC410MNF-RH motherboard. From what I could gather, it’s an ATi chipset. Do you reckon that could work with Win98?

For now I’m leaning toward getting a SB Live! 5.1 card and running WinXP. I can always get an Audigy at a later date and dual-boot Win98 if needed.

If you want to use DOS programs in Win98 mode, on my Win98SE system, I was only able to get UMBs and EMS using UMBPCI. If you can't get UMBs or EMS on your system, try that. 😀

AndreaColombo86 wrote on 2025-07-15, 21:13:

Thanks again.

The P4 3000Mhz, which is the machine I’m keen on, has a Gigabyte 8TRC410MNF-RH motherboard. From what I could gather, it’s an ATi chipset. Do you reckon that could work with Win98?

For now I’m leaning toward getting a SB Live! 5.1 card and running WinXP. I can always get an Audigy at a later date and dual-boot Win98 if needed.

im not sure how compatible ATi chipsets are with win98, i dont really hear people talk about them when it comes to 98 or just in general, if your going pentium 4 (which is a good choice for 98/xp) i'd play it safe and stick with either an Intel, VIA or SiS chipset.

Not familiar with that chipset either but it's not looking good for Win98 compatibility after a quick search.
https://theretroweb.com/motherboards/s/gigaby … -1-1-oem#driver

It has native IDE so you'll still probably be able to install Win98 but it won't recognise on-board components like USB, SATA, Audio.

GemCookie wrote on 2025-07-13, 15:13:

The Windows XP partition can be formatted from a Windows 98 boot disk. Navigate to the installation medium and run "extract ebd.cab format.com"; this will make the format command accessible. Formatting the partition from a later Windows installation medium is also an option.

yes, but dosbased format.com can only provide a FAT/FAT32 partition not ntfs.

btw, I found your signature that "GA 8i915p duo" without win9x, did you tested win9x on it? for I always hangs on "detecting pnp hardware", even ghost a installed win9x cannot get start menu, only a empty desktop.

mantis2001 wrote on 2025-08-08, 04:44:

yes, but dosbased format.com can only provide a FAT/FAT32 partition not ntfs.

btw, I found your signature that "GA 8i915p duo" without win9x, did you tested win9x on it? for I always hangs on "detecting pnp hardware", even ghost a installed win9x cannot get start menu, only a empty desktop.

I tested both Windows 95 and 98 SE on this motherboard, but had absolutely no luck running them. Most of the time, the display adapter would conflict with System board extension for PnP BIOS, making GPU driver installation impossible. I somehow fixed this on two occasions; however, installing the graphics driver would then make the system unusable. ForceWare 66.94 and 71.84 made it reboot right after the splash screen, while 77.72 and 81.98 triggered a Windows protection error.

I would also get Runtime error 202 followed by a system hang from time to time, especially during software installation. I encountered a similar issue on a Haswell laptop; I solved it by adding the following lines to system.ini:

1[vcache]
2MinFileCache=1024
3MaxFileCache=1024

yes, since I failed many 915/945/965 chipsets on win9x, I must admit via lga775 variants seems much better.

ott wrote on 2025-07-12, 18:04:

I use this way (NTLDR + Win98's bootsect), each OS thinks it's installed on drive C:.

my steps, fyi.
1). partition 1*primary, (1*ext+n*logical,optional) left enough space for nt5, then install win9x.
2). create reserved free space as 2nd primary, format as ntfs, but keep active on 1st primary which install win9x
3). install nt5 on 2nd primary, you will got bootsect.dos file and other nt5 boot files, backup them. your nt5 system vol is not "c:", it will be "e:" or "f:" etc,
4). make 2nd primary active, format before or during install nt5 onto it again, you will got "c:" for system vol. in nt5 you can hide win9x vol letter and keep all other vol same drive letter as win9x.
5). make 1st primary active again, reboot, if everything is ok then your win9x & nt5 will boot as expected with system vol called "c:"