Ok it seems solved my problem. the problem was that in IIS instead of permission to network service, had to give permission to asp.net.

but i have now another problem. just while installing the database script. in the wizard mode, i pass the connection to the db and its information successfully. but when i click on the next step, where it should install the db scripts, it looks as it it is running but nothing happens. in the bottom left side corner of the browser i can see some icon indicating some possible errors on the page. Can any one tells me what is going on here?

many thanks

Hossein