MSJAVA.DLL

In my W2K,SP2, WINNT\SYSTEM32 folder there is a msjava.dll file version 3805 that I want to replace with msjava.dll version 3802 because this is the version required by a certain application. I cannot rename, (if renamed, it replaces itsself)deleteor overwrite this file. If you delete the file it does not complain, but it does not go away. Any ideas out there?