Help! a problem with updating heroes of might and magic 4

[Idanush]

Hi.
When I execute the 1.3 patch in Heroes of might and magic 4, when it gets to the heroes4.exe file it opnes an error message that says "old file not found" and that the current file hase the same name but doenst containe the same data..

why is that? where can I get the "old file"?