Hi, for this problem i use cacls.exe which displays or modifies access control lists (ACLs) of files. I think it is a part of some admin tools set... See this: http://www.ss64.com/nt/cacls.html Joc
I was blind... Everything is worked with setup.iss... Just delete first the installation directory in "Program Files" or you will get this -3 returncode! Joc