China DOS Union

Has anyone noticed that when installing 2000, after the first reboot it can boot from the hard disk without going into the BIOS to change anything (it was originally set to boot from the CD-ROM to install the system)..... In other words, it makes CD-ROM booting ineffective. Does anyone know how this is done?

Generally speaking, it boots from the CD first and then switches to booting from the hard disk...
In other words, after the first reboot it is still booting from the CD... but the default option after CD boot is to boot from the hard disk, so if you don't interfere it will boot from the hard disk!

There is a program jo.sys that does exactly this.
It displays a menu and lets you choose whether to boot from the CD or from the hard disk.

Another method is to display "press any Key to Boot from CD ..." at startup, that's roughly what it means. Translated into Chinese, it means press any key to boot from the CD... After a few seconds of delay, if you don't press a key, it will boot from the hard disk.

Basically all the boot CDs I've seen are like this...
I don't have a genuine 2000, so I don't know whether the genuine 2000 is also like this...
But I do know that a Windows preinstallation environment (WINPE) CD can be made this way (the second method); that PE builder software provides this function.