[BUGS] installation bug

[Ludvík Adamec]

Hello, I have tried to install postgresql many times, but every time i have in instalation error: Problem running post-install step. Installation may not completely correctly Error reading file C:/Program files(x86)/PostgreSQL/8.4/data/postgresql.conf 
I also tried different version of postgresql...also i tried to install in OpenGeo application pack.....nothing works. 
Can you help me please? 
Thanks