Sth. about InnoSetup's passwords

thanks for your replies.
yes,we can patch the internal set const PasswordHashString with our values.
we can find that in the is-*****.tmp file and patch the tmp file,this way we can pass the install process.
But can we patch the setup.exe other than the tmp file ??
If searches the const hashstring in the setup.exe, the result Ofcourse is null,because the file is compressed.
I have traced the setup.exe to find the decompress procedure,it seems the decompress algorithm make sb. crazy.
So another problem is how to find the const hashstring in the setup.exe ? In other words is that how the innosetup compress and decompress the file ?