Help! I have a problem with heroes of might and magic 4

[Idanush]

When I try to update Heroes 4 from version 1.0 to 1.3, I get an error when the update gets to the file heroes.exe

Here is the exatct message that appears when the update gets to the hereos4.exe file:
Old file not found. However, a file of the same name was found. no updates done since the contents do not match.