So the question is, what changed on the machine in the last few weeks?
Did you intall any software?
Change any settings?
The fact that it is asking you to insert a CD indicates that there is some startup item that is linked to a file on the CD. That's a misconfiguration.
On OS9, your System can be bloated for RAM usage depending on the number of Extensions and Control Panels that are loaded at startup. These can be turned on and off with the Extensions Manager (Apple Menu; COntrol Panels: Extensions Manager) There are many extensions that can be safely turned off, far too many to go through here. You can find information at
http://www.informinit.com/ or better yet, get your Mac guy on the phone and go down the list with him one at a time to turn them on or off as required.
Also, you may have inadvertently turned on a RAM Disk, (a feature that creates a "disk" image in memory) which would consume memory, this should be turned off.
In the Startup Items folder in your system folder are the items that launch automatically when you boot the Mac. Please drag out whatever items are in there and create a folder for them (if there isn't one already) called "Startup Items (Disabled)"
Virtual memory: This is where the Mac uses a large chunk of the hard drive to supplement the RAM Memory of the machine. With 640 Mb on OS9, you should not neeed VM turned on. Go to Apple Menu: Control Panels: Memory and turn it off.
> And whichever annoying little person just told me to empty the trash...
We only know what you tell us, Lizi. If you post a panicked cry for help that has no details about what machine, what OS, what you have tried so far, or anything, then we have to start at the bottom. Be more definitive about your problem and you won't have people assuming the least. And it won't waste so much of our time.
Edits: Other people type faster