So does this mean that I will have to reinstall OS 9 on my system?

Maybe not. Go to the disk that has OS 9 installed. Double click the system folder named "System Folder" (not "System", which is the Mac OS X system folder). Select the Finder file and do "command (or Apple key)-I" (or Get Info in the Finder File menu). If the version says 9.1 or later (mine says 9.2.2), then you have a version of OS 9 that is supposed to support Classic.

If you do not have at least version 9.1 installed, go -> here

If you have version 9.1 or greater, try -> this If this doesn't work, then you'll have to reinstall.

Good luck.
Who serves his fellows, is of his fellows greatest - Chingachgook (by legend)