Unfortunately the information you gave us is not enough to determine what might be the reason for your problem. Would you please give us more details about the steps you are taking when installing Sitefinity2.5? Do you get any pages related to Sitefinity
to work? Are you talking about 2.5 or 2.51 version?
It is normal not having the folders Primavera/Database and BlogSpace/Database, in Sitefinity2.5 as they are changed to App_Data folders.
Thank you in advance and we are looking forward for your replay.