Thanks for the suggestion. Let me summarize what i did;
1 ) The setup file is an .msi file so when i right click on it there was no "Run as Administrator" menu item in the context menu
2 ) I open a command line as administrator and run the .msi file but it gave an error yesterday
3 ) At the same time, i was turning on an IIS feature "IIS Metabase and IIS 6 configuration compatibility" on "Turn Windows features on or off". It took ages yesterday ( i started in the yesterday morning, it didn't finished yet when i was leaving yesterday evening
) so when i came back this morning i saw that this feature added.
4 ) I ran the .msi file again as it was described on bullet 2 then bingooo, it worked
.
Thanks again for the suggestion. Even though i'm not sure, i marked your reply as the answer. Now i have another problem and i will open a new post