Q: iBook g4 tried to install classic then after reboot it only showed the missing folder

You'd need to use the original Installer (content on disc2 of grey-label included software kit)

to install the correct Classic 9 version that shipped with Tiger 10.4.x in the iBook G4 model.

My iBook G4 (mid 2005) 1.33GHz 12-inch last model has both discs of the kit; however as

time has gone forward, the original discs do not always install all of the original software

so I had to use Pacifist (charlessoft software/older version) and in OS X extract various bits

from the original disc media and use Pacifist to also install them. This by-passes an installer.

However, if you have another Mac old enough to run MacOS 9.2.2 directly, (boot up) you

could copy (drag/drop) that into another partition or to external hard drive the iBook G4 can
see, and it could be detected as a Classic 9 system (non-boot) in the later iBook G4.

Also if you have the iBook G4 install restore disc2 (classic install) that classic version can be

used in an older PPC dual-boot or OS9.2.2 boot early pre-x mac to create a startup system

that can run an older computer series.  Some of the control panels & extensions are missing.

Copies of software off the internet are not viable; are suspect, and probably illegal. If you have

the install-restore disc set from any of that vintage computer (even if the old Mac was sent off

to the recycle) the orphaned software can be useful. It may not be able to use original 'installer'

so that is where you can experiment with obsolete items to learn more about them.

And if you had an ISO or disk image, you may be able to use it, but would need to have FireWire

external hard disk drive and/or optical drive; these need to have an 'oxford-type' chipset to boot

the PowerPC hardware. Also these would be useful if you create & use boot-able OS X clones.

Sorry I don't have an answer to your question... as I just happened across this section.

Other probabilities could have occurred; you did not specify

with clarity if there was indication of damages to the Start Up

Drive - the system that had previously been running the Mac...

Or if the folder you had acquired online from some undisclosed

source, was the defective item after a restart. ~ Either way, an

older MacOS 9.x Classic won't be a boot volume in G4 iBook.

As some time has passed and you've not detailed the exact

meaning or hinted at other things you've tried, I may throw this

out there... Support articles about how to try & start a Mac that

has a Question Marked folder on the desktop. Some 'flash' &

others are just an icon, these imply the startup files aren't seen

by the Mac hardware. This may also mean it is confused; or if

some odd system you got from internet, damaged the Mac OS.

•How To Fix Common Mac Startup Problems [MacRx] | Cult of Mac

Jul 23, 2010 - The flashing question mark or a circle/slash means your Mac can't

find a valid startup disk. This can indicate a corrupt installation of Mac OS X...

The original install restore system disc set can be used to test

& repair the hard drive; also re-install a working system; also

to attempt to make the computer to restart from system on HDD.

•Troubleshooting Mac OS X installation from CD or DVD - Apple Support

https://support.apple.com/en-us/HT201817

•Resolving Disk, Permission, and Cache Corruption - The X Lab

www.thexlab.com/faqs/repairprocess.html

• If a flashing question mark appears when you start your Mac - Apple Support

These newer ^ articles for on-line use displaced older better vintage ones

w/ off-line methods of troubleshooting or re-installing older MacOS9 or X

suggest using 'Recovery.'  {While these vintage machines do not use an

OS X that would have or use that new contrivance nor internet recovery.}

Because the problem you state may likely have occurred as a result of

a downloaded system from unknown sources online, unsupported or

perhaps even an illegal copy (that may be corrupted) there may be more

involved in the symptom you stated. Or your Mac may just be confused.

In any event...

Good luck & happy trails!