Only for my own personal educational purposes tried this.
Repeat: For my own personal educational purposes.
Added a winME book disk
This image will not boot - why?
It hangs the PC and only a hard reboot frees my system.
Any idea why it doesn't work?
I also had the problem in Gujin.
If my memory does not fail, when the real DOS boots, it assumes there wasn't anything but BIOS before, and so it forces the size of the real-mode RAM to 640 Kbytes (it does not read the result of interrupt 0x12 - probably because some BIOS were buggy).
If you had a TSR loaded around 639 K, like a floppy disk simulator, it is erased by the real DOS but its interrupt vector INT 0x13 will still point in this area: garantied crash.