Where did my Classic go??

[Sherry]

Hope someone can help me, as I am lost.  Yesterday I used a program that 
uses Classic.  I closed the Classic program and then opened a program in 
OS X.  Today I cannot access Classic mode.  I get an error box stating 
"To Start Classic You Need Mac OS 9.1 or Latter Installed.  See Your 
Documentation For Instructions On Installing This Software."

My HD shows a System Folder with I think all the right stuff.  I Get 
Info on some of the items, and then all show OS 9.2.2.   Do I just 
install OS 9 again from the install disk?  Do I need to remove anything?

I've only had this G4 for about 5 months, so I am still trying to learn 
OS X.

PowerPC G4 933
Mac OS 10.1.5

thanks for any help.

Sherry

PS: I do have OS 10.2, but have not installed it as yet.  Am a little 
nerves about it.