If I use Resource Hacker or PE Explorer and edit the resources of an executable (e.g., replace the standard icon with a fancy one) the executable is frequently corrupted.

Can anyone explain to me why this is happening and, if possible, how this problem can be fixed? (I know for sure that the executable does not perform a CRC check or something.)

Many thanks.

This may occur if the resource section is not at the end of the file, as unless you replace the existing icon with one of the *exact* same size, it will overwrite the sections following. Most resource editors are not smart enough to relocate the resource section to the end of the file.

Another possibility is that it is a single-section PE, and everything is in the same section, with some other code or data following the resources. Many resource editors cannot handle this well.

Use LordPE to determine where the resource section is located, and determine how to move it to the end of the file.

Thank you.