98SE would be my pick.
ME you lose the (easy) method of exiting to DOS.
2000 and XP are not necessary unless you are using something that can utilize more than 1 CPU core, my opinion of course.

these systems are no longer daily drivers. terms like 'sluggish' kind of lose their meaning when you're no longer multitasking. boot > install game > play game > uninstall game > shutdown are all single tasks.

don't get me wrong...xp is a modern operating system and can be a daily driver, but not without sse2 which leaves all pre-p4 systems off the table.

i dual boot xp & dos on my athlon xp build. win98se is installed on the dos partition, but never used. i also have grub4dos installed on my xp boot menu which is absolutely brilliant for booting any errant cd iso or floppy img file from hdd (hardcoded to search for any file named boot.iso/img on active partition).

512mb is fine for xp singletasking.

+1 for WinME, especially with the OP's hardware and inclination towards Windows based games. With all the hindsight and drivers we've had since then, WinME is by far the best Win9x experience for me. Win98SE is ok and maybe more nostalgic, but you will be tearing your hair out with things that were installed and working-but now they're not for no apparent reason-kind of tantrums from the OS. Funny that WinME's problems were long solved in the majority whereas Win98/Win98SE's many, many problems still remain to this day and nobody bats an eye or complains in the slightest

leileilol wrote on 2022-06-12, 06:24:

RandomStranger wrote on 2022-06-12, 05:59:

There aren't much to justify using it on an active build other than as a curiosity.

High mouse rate and USB storage are two reasons. There's also some support for later versions of DirectX 9. This P3's a strong candidate for a ME machine.

The ME shame is overplayed so much to the point, some had been outraged about the Win98 patchwork 'service packs' that change their OS's identity to ME. 🤣

Now I'm tempted to install ME on my P4 2.4ghz. system I just built. Curiosity may be my undoing 😁

My similar system has TWO Windows ME installs and a Win98SE install. They both held up better than 98SE. My DOS compatibility is broken anyway with the SBPCI128's legacy drivers conflicting with the PCX2.

Saidian wrote on 2022-06-11, 16:56:

Long as I can run the games I listed in Win98SE I guess I'll go with that then.
All I'm focused on is getting the best performance with the hardware I'll have, don't want to install XP if it's just gonna bring down the overall performance.

Windows XP is a lot heavier to run than Windows 98, they are in different leagues really, so it will be reducing performance a lot. I like the advice in the first post for Windows 2000. You shouldn't miss out on a lot compared to Windows XP and it is a whole lot lighter to run. I used a Windows 2000 netbook for college up to a few months ago and I gotta say: I wasn't missing out on hardly anything. Windows 2000 is NT5.0 and XP is NT5.1, so under the hood they are very similar. Most of the software that runs on XP will run just fine as long as the installer doesn't lock you out when it detects Windows 2000.

That being said, I usually install the oldest operating system I can get away with in order to get the best performance. I'd advise you to do the same. Just check what the games you're planning to run need at the minimum. I usually end up with Windows 95 because of this. I presume you will need something slightly newer.

Yeh I'm leaning towards potentially 2000 at this point once I have my final parts at the start of next month but I'll play around with 98SE on the setup I have now when my backup GPU arrives.

By the way, this is why I use mobil racks in most of my retro PCs. Switching hard drives takes something like 3 seconds and I can "multi-boot" as many operating systems as I want without any one affecting the others in any way. If I want to experiment something, let's say ME, I just dock a new drive and try it out. If I dislike it then I can return to the previous OS completely set up like nothing happened.

RandomStranger wrote on 2022-06-14, 19:11:

By the way, this is why I use mobil racks in most of my retro PCs. Switching hard drives takes something like 3 seconds and I can "multi-boot" as many operating systems as I want without any one affecting the others in any way. If I want to experiment something, let's say ME, I just dock a new drive and try it out. If I dislike it then I can return to the previous OS completely set up like nothing happened.

I suppose you use a second storage device internally for data storage so all your OS drives have access to the same data set?

Tetrium wrote on 2022-06-15, 11:29:

RandomStranger wrote on 2022-06-14, 19:11:

By the way, this is why I use mobil racks in most of my retro PCs. Switching hard drives takes something like 3 seconds and I can "multi-boot" as many operating systems as I want without any one affecting the others in any way. If I want to experiment something, let's say ME, I just dock a new drive and try it out. If I dislike it then I can return to the previous OS completely set up like nothing happened.

I suppose you use a second storage device internally for data storage so all your OS drives have access to the same data set?

Nope, a 500GB network storage dedicated to my retro VLAN.
I also have a PC I use to set up other PCs, the previously mentioned 433 Celeron Win2k build. That has an internal storage and a mobil rack bay to copy over drivers if necessary.

Saidian wrote on 2022-06-11, 11:48:

I have been wondering past few days if the system I'm building would be better served with having 98 or XP as the OS. […]
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I have been wondering past few days if the system I'm building would be better served with having 98 or XP as the OS.

I still have a bunch of parts to get but I've nailed down the main 4:

Pentium iii 1ghz Coppermine
DFI CS61-EC Motherboard
512 PC133 SDRAM (Max the above supports)
Nvidia Geforce 4 Ti4200
Sound Blaster Live SB0220

I do have a few older pre 1995 DOS games I want to play but considering I can use Dosbox for those (right?) I'm wondering if XP would be a better fit than 98 considering the majority of my library playing games up to Freelancer, KOTOR and possibly World of Warcraft Vanilla. Will be running a good amount of console emulation too.

Will the higher requirements of XP have a negative impact or will it not really matter?

Thats Windows-98se hardware.
I would reduce the RAM to 256mb for best performance.
512mb of ram actually slows down the computer by just a little.

leileilol wrote on 2022-06-14, 18:41:

My similar system has TWO Windows ME installs and a Win98SE install. They both held up better than 98SE. My DOS compatibility is broken anyway with the SBPCI128's legacy drivers conflicting with the PCX2.

PCX2 is something I'd like to get a hold of but that is pure fantasy for obvious reasons. Really should have got into this hobby 12 years ago!