It needs clarifying what you mean as "Windows NT"...

Modern Windows versions - based on NT, indeed?
Or NT versions contemporary to 9x - primarily 4.0, optionally 3.51 and 2000 as well?

The cooler looking disk defrag tool in Win98.
Crashing drivers
Not running out of system resources and having to restart because you cant have any more icons.
Not polling optical drives when you open My Computer (only those with a CD changer will get this though)

Holding down Shift to "restart" only Windows rather than the whole PC after making a major config change

If comparing to XP and below
9x was a lot less demanding on hardware
9x simplicity, like the time I "hacked" a friend's computer by temporally moving the pwd file out of the windows folder to disable his password so I could copy all his games 😀

If comparing to modern OS's
User interface was streamlined and efficient. Something thats getting worse not better as time goes on. OP's mixer remark is an example.
Classic start Menu. Modern search function is fast but sometimes it still lags while you search for an app. Never had that issue on a menu with static shortcuts.

Grzyb wrote on 2025-04-02, 23:00:

It needs clarifying what you mean as "Windows NT"...

Modern Windows versions - based on NT, indeed?
Or NT versions contemporary to 9x - primarily 4.0, optionally 3.51 and 2000 as well?

I never used WinNT4 and 5 so I didn't bring them in comparision. But it still falls in the question.

BEEN_Nath_58 wrote on 2025-04-02, 18:55:

...
The ability of change MIDI/CDaudio/WAV volume is another one. Modern mixer throws everything into 1 stream so separation is not possible. It removes the ability to play games only with the MIDI/CDaudio and reading the text instead of listening to their chatters

The old mixer with separate global sources for Midi, Line-in and CD audio is not Win 9x specific. It works the same way on WinNT4/2000/XP.
MS introduced the new audio stack in Windows Vista which resulted in the reduced mixer with a single wave source per application.

Falcosoft wrote on 2025-04-03, 07:06:

BEEN_Nath_58 wrote on 2025-04-02, 18:55:

...
The ability of change MIDI/CDaudio/WAV volume is another one. Modern mixer throws everything into 1 stream so separation is not possible. It removes the ability to play games only with the MIDI/CDaudio and reading the text instead of listening to their chatters

The old mixer with separate global sources for Midi, Line-in and CD audio is not Win 9x specific. It works the same way on WinNT4/2000/XP.
MS introduced the new audio stack in Windows Vista which resulted in the reduced mixer with a single wave source per application.

Yes I was referring WinV+ in this scenario, I didn't have much of those pre 2000s multi mixer games in the WinXP era to make it my "missing point".

On XP the mixer is still a little bugged, or fixed than the 9X mixer. Certain CD audio games don't function in the same manner. Eg: Interstate 76

I like not having IE installed (only early W95 had this).

An OS so small you could install it from a small stack of floppy disks.

Windows NT 4. Great OS. Many service packs. Best icons and startup sound. But why no PnP. Why orphaned DirectX. Slow start. High memory needs.

The ability to launch Win9x from DOS and then (unofficially) exit back to DOS was nice.

The main thing missing from NT is the ability to fall back on DOS/BIOS API for disk access instead of just going dead with a 0x7B BSOD. Always and forever.

BEEN_Nath_58 wrote on 2025-04-03, 07:16:

....

On XP the mixer is still a little bugged, or fixed than the 9X mixer. Certain CD audio games don't function in the same manner. Eg: Interstate 76

This problem definitely has nothing to do with the mixer API. It's much likely MCI or timing related. You should know what the problem was exactly since it seems you have already found the solution according to this thread:
MCI cdaudio not repeating (looping) on modern Windows systems

The ability to hit Esc after a bluescreen and continue working.

Falcosoft wrote on 2025-04-03, 10:12:

BEEN_Nath_58 wrote on 2025-04-03, 07:16:

....

On XP the mixer is still a little bugged, or fixed than the 9X mixer. Certain CD audio games don't function in the same manner. Eg: Interstate 76

This problem definitely has nothing to do with the mixer API. It's much likely MCI or timing related. You should know what the problem was exactly since it seems you have already found the solution according to this thread:
MCI cdaudio not repeating (looping) on modern Windows systems

Not this, the CD audio in game doesn't want to get to 100% even when CD audio mixer is at 100%. Could be any of the SP4 update clashing with something else.

BEEN_Nath_58 wrote on 2025-04-03, 10:20:

Not this, the CD audio in game doesn't want to get to 100% even when CD audio mixer is at 100%. Could be any of the SP4 update clashing with something else.

I never understood why people install these "unofficial service packs" on WinXP if the main goal of the system is retro gaming. Still waiting for someone to point out a game which had official WinXP support at release but won't work without said hodgepodge of official and unofficial "fixes".

From my experience, simply having the official SP3 installed is enough to run any WinXP compatible game made before 2010 or so. You may need to update DirectX 9.0c to the latest release too, but that usually ships with the game which needs it.

BEEN_Nath_58 wrote on 2025-04-03, 10:20:

Falcosoft wrote on 2025-04-03, 10:12:

BEEN_Nath_58 wrote on 2025-04-03, 07:16:

....

On XP the mixer is still a little bugged, or fixed than the 9X mixer. Certain CD audio games don't function in the same manner. Eg: Interstate 76

This problem definitely has nothing to do with the mixer API. It's much likely MCI or timing related. You should know what the problem was exactly since it seems you have already found the solution according to this thread:
MCI cdaudio not repeating (looping) on modern Windows systems

Not this, the CD audio in game doesn't want to get to 100% even when CD audio mixer is at 100%. Could be any of the SP4 update clashing with something else.

The mixer API on WinXP works fundamentally the same way as on Win9x but in case of WinXP there is a much higher chance that CD audio uses digital audio extraction so the analog CD audio mixer source (that most games select by default to adjust CD audio volume) has no effect on it.

Joseph_Joestar wrote on 2025-04-03, 10:26:

I never understood why people install these "unofficial service packs" on WinXP if the main goal of the system is retro gaming.

I don't know for others but I still use it for the forbidden act- "browsing internet" while being logged out. I previously installed all the updates separately based on needs but certain new apps needed newer Libs so I just slapped it on top of the OS and they never complained about the OS version (without using OneCore)

I occasionally boot into XP x64, in recent times, mostly to check newer web browser backports, sometimes I'd also compare an old game on XP vs 10. I think the chance of encountering some exploit that'll target the old OS is extremely unlikely.

Updates were (still are?) a nightmare with Windows, if you wanted fully updated OS, you needed a crapload of them. I still remember using the old computer (that would be 24 years old today) and how update scans would take forever. To get that XP x64 running, I used community made ISO I found years ago that has OS updated to whatever was current in 2011 or 2012, don't recall exactly. Plus some crypto32 and maybe another update that had to do with something I tried getting working.

Due to how they're implemented and considering 99% of time things that bother me aren't fixed with updates anyway, I just don't bother with them most of the time. When I read about Legacy Update, I thought cool, maybe I can get that installation fully updated. Didn't work, Windows Update service just spinned in an infinite 100% CPU core utilizing loop.

Just don't bug me with updates, 🤣!

Faster startup and shutdown.
Back when I upgraded my main rig from Me to XP I remember how every boot, reboot, and shutdown process felt glacially slow. Even after defragging, turning off services, using BOOTVIS, checking if DMA was enabled— no matter what I did made XP boot or shutdown as quickly as Me.

MSConfig
Windows 98/SE/Me had it. NT line didn't get that nifty little utility until XP.

More likely to survive switching hardware configurations without a reinstall
This is more of a personal anecdote but I've been able to install Windows 95/98 on one machine, pop out the hard drive, put it in a second machine, and be able to boot it and only need to install a couple of different drivers for it to work properly again. 2000/XP in my experience always needed to be sysprepped to work again and even then I've had varying degrees of success without throwing in the towel and doing a complete reformat/reinstall. I also LOATHED how 2000/XP never offered an easy way to switch over from IDE to SATA drives or vice versa without relying on BIOS hacks, busting out your old floppies and spare floppy drive, or futzing with slipstreaming install discs. One of the few things that Vista got right was being able to install storage drivers from a CD, a flash drive, or even a network share from the setup interface.

You can copy msconfig from XP to W2k and it will work. You can also copy the win98se version to NT and it will work, once you get over a bunch of warnings.

I must have been lucky because I've moved hard drives of various Windows versions around and never had to sysprep or reinstall. Just needed a few drivers added. Obviously have to use supporting hardware of course.