I need to change default instalation path and i wonder if i can implement this to New Build of my Windows Installation.

I need it to add more programs to my instalation.

Simply i need add these key to windows instalation registry:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion
ProgramFilesDir C:\Program Files\Programy

It's simpler to use nLite Unattended page for that, search there Program Files path.