This is a good start for you:

Minimum OS Class Required: Windows XP - https://www.mobygames.com/attribute/sheet/attributeId,266/
Minimum OS Class Required: Windows XP SP1 - https://www.mobygames.com/attribute/sheet/attributeId,1098/
Minimum OS Class Required: Windows XP SP2 - https://www.mobygames.com/attribute/sheet/attributeId,1099/
Minimum OS Class Required: Windows XP SP3 - https://www.mobygames.com/attribute/sheet/attributeId,1231/

I am not sure I understood your question, are you building 98 or XP machine?

Compatibility is a complex topic with many nuances so you would probably need to be much more specific to get any meaningful answers.

Lol, "Duke Nukem 3D: Atomic Edition" required Windows XP?

Never trust Mobygames.

I know that some games that say that they require windows xp still work on win9x. I was just wondering if anyone knows what was the main reason for games to become incompatible with win9x when they did. If it was directx version or perhaps they need some other libraries from winxp?

Baoran wrote on 2020-02-20, 11:25:

I was wondering about when games stopped working on win9x. Was it when they started using directX 10 or was there other reasons why a game from WinXP/Vista period wouldn't work on Win9x?

Hello there! Are you asking about technical or official limits ?
Technically, Win9x can run some of the DirectX 9 stuff that is labeled "XP and higher" if KernelEx is installed (along with GDI+ and Unicode DLLs).
In fact, Windows Me could have a current DirectX 9 that's as late as 2008.
Edit: The official DirectX Redist. for both Win9X/XP is from 2004. After this one is installed, you can upgrade up to version 2008 (on Win Me).
Also, if you can't install DirectX 9 on your PC, just start with installing DirectX 9a and then upgrade to the 2004 version.
Some versions of DX are available at FalconFly's mirrors.
http://www.falconfly.de/3dfxarchive.htm
https://3dfxarchive.com/directx.htm

Baoran wrote on 2020-02-20, 11:25:

I am considering how fast a pc should be that you would need to install WinXP to be able to play all the games that the pc could run performance wise.

That's tricky. Some people kept Windows XP running on Windows 7/8 hardware, even.
Some early intel i7 CPU, GeForce GTX 750 TI graphics card, 16GiB of RAM, 2TB HDD..
While others stopped using XP when Vista came out (say Athlon 64 x2 CPU, 2GiB RAM, GeForce 9600/ATI Radeon X850 XT, 500GB HDD).
Personally, I started using XP on a Pentium MMX 166MHz with 2GB HDD and 64MiB of RAM.. 😀
Edit: The numbers are just random to give an idea how extremely different things could be.

Jo22 wrote on 2020-02-20, 14:39:

Edit: The official DirectX Redist. for both Win9X/XP is from 2004. After this one is installed, you can upgrade up to version 2008 (on Win Me).

So Windows ME can run a newer version of DirectX than 98SE? I didn't know that.

That implies that there are games that run under ME that do not run under 98SE, or at least games that run better under ME.

Jorpho wrote on 2020-02-20, 17:00:

Jo22 wrote on 2020-02-20, 14:39:

Edit: The official DirectX Redist. for both Win9X/XP is from 2004. After this one is installed, you can upgrade up to version 2008 (on Win Me).

So Windows ME can run a newer version of DirectX than 98SE? I didn't know that.

That implies that there are games that run under ME that do not run under 98SE, or at least games that run better under ME.

To be honest, I wasn't aware of this before also. But Falconfly has a detailed chart of DirectX versions that tells which one is supported.
Apparently, Windows Me seems almost on XP level in terms of compatibility, which would make sense since they are both sort of soulmates.
With KernelEx and the more recent DirectX 9 runtimes, some of the newer XACT/XNA/XAudio stuff *might* be running even.
Anyway, I'm just a layman here. Compatibility with the .Net Framework might be a limiting factor here, also.
.Net version 2 is perhaps the last to be officially supported on 9x.
https://en.wikipedia.org/wiki/Cross-platform_ … o_Creation_Tool
https://en.wikipedia.org/wiki/Microsoft_XNA
https://en.wikipedia.org/wiki/XAudio2

Edit: Typos fixed.
Edit: This has to be tested, but.. Upgrading to Me *perhaps* isn't necessary if 98SE has one of these inofficial "Service Packs"
or NUSB is installed, since they contain Me system files essentially. Well, assumed they contain the Me kernal and some helper files.

Apparently, Windows Me seems almost on XP level in terms of compatibility, which would make sense since they are both sort of soulmates.

Falconfly states, that this information might not be correct. To be fair though, there's practically zero games you would want to run (if able at all) under Win 9x / ME, which require DirectX 9.0c 2007+ updates.