Have you checked the cartridge to be free of defects?

Edit:

Z750 can read 100, r/w 250. You could try a different one. Unless it just hangs with this one motherboard; you could make a quick test with a non-750 unit.

Yes, there are no problems with the disk inserted, the boot problem is there with and without a disk in the drive.

I am using nusb33 drivers for removable flash disk media.

ElectroSoldier wrote on 2023-12-06, 14:51:

Yes, there are no problems with the disk inserted, the boot problem is there with and without a disk in the drive.

Maybe it's incompatible with a 750 drive. I don't have one so I can't tell from experience.
100 and 250 never gave me issues, only once with a failing disk.

Does the same problem also exists with other kind of USB drives? Some retro pc's I have don't want to boot if I have an USB flash drive inserted for example.

No, if I plug in a regular Kingston flash drive it just boots up.

If you try the drive in another system does it hang up that system while it boots? If you plug in the drive after windows loads does it function properly or hang the system as well?

When I plug it into a Windows 10 machine, and Windows XP it works no problem, they just boot.
When I change the USB port of the GX270 same problem, Win98 wont boot, it just sits there on the start up screen. But not frozen, its still amimated, there is just no HDD activity at all.

And If I unplug it at the point its locked nothing happens, I have to press the power button to shut it down and then it does a hard disk scan or asks if I want to boot in safe mode.

ElectroSoldier wrote on 2023-12-07, 17:07:

When I plug it into a Windows 10 machine, and Windows XP it works no problem, they just boot.
When I change the USB port of the GX270 same problem, Win98 wont boot, it just sits there on the start up screen. But not frozen, its still amimated, there is just no HDD activity at all.

Does W98 boot with a regular cd?

If I insert a bootable CD then it boots from it.

Windows 98 as it is installed will boot normally when the Zip drive isnt inserted, or if I unplug the power cord

ElectroSoldier wrote on 2023-12-07, 17:12:

If I insert a bootable CD then it boots from it.

Windows 98 as it is installed will boot normally when the Zip drive isnt inserted, or if I unplug the power cord

Try with another video card, not nvidia.

ElectroSoldier wrote on 2023-12-07, 17:07:

When I change the USB port of the GX270 same problem, Win98 wont boot, it just sits there on the start up screen. But not frozen, its still amimated, there is just no HDD activity at all.

Is the 9x logged boot any use in this case? F8 at boot (or whichever key it was to get the menu just after POST, maybe F5), and there is a logged boot choice, I think. Log a failed/hung boot, then have a look at the end of the file, and perhaps the Gods of Redmond will grace you with a hint.

I'll give that a try when I'm home.

No real help there...
Last entry is loading the audio mixer.