I have a corrupt CSAPI3T1.DLL and don't know what it is or does??

Gateway 233 P-II with 320RAM, Win98SE & Office 2000. I went to
Start/Program/Accessories/System Tools/
System Information/Tools/System File Checker and ran the application.

It found CSAPI3T1.DLL corrupt. I had nor do I have ANY idea what this is.
Using Start/Find/Files or Folders on the hard drive C:\, the system does not
fined the file, however it is located at C:\Program Files\Common
Files\Microsoft Shared\Proof along with 7 or 8 others.

How do I safely fix this and in what manner? Thanks