Compact files vs project packs

[friend]

Good day to all i'am a PECompact newbie and English it's not my
native language, so sorry for any understanding.

I will try explain the problem i'am facing now, maybe i'am doing
something wrong but i couldn't find the way out.

I have one app.exe file (10.8 MB before compact and 1.13 MB after
compact).

I use Inno Setup to pack my distribution project,  after pack the
project using both exe files i reach almost the same pack size
14.4 MB. Any reason for that ???

Regards - Friend

[Jeremy Collake]

Installers, self-extracting archives, and similar files contain mostly already compressed code and data. Since they are already compressed, they can not be compressed much further, and may sometimes even grow in size.