Following files are active :
ApplySession failed during prerequisite checks: Prerequisite check "CheckActiveFilesAndExecutables" failed.
System intact, OPatch will not attempt to restore the system
OPatch failed with error code = 74
Change file \Oracle\product\10.2.0\client_1\bin\oci.dll to oci-1.dll (As you like)
Now execute OPatch. Issue resolved.
Big thanks to this blog author