You can't. The signature is created when teh program is compiled by the
programmer. After that it doesn't change.
You can often get this message if an EXE file has been corrupted: for
example if it was damaged during download, or while being unzipped.
I don't know what "Kompzer" is, but if it is an application you
downloaded from the Internet, the best step would be to download it
again. If it still fails, contact the vendor of the software for further
help.