First i installed Odoo 9.0-20160923 openerp on my windows it installs PostgreSql and Odoo files along with it successfully and it was perfectly working too, for some reason i didn't want this version so i just uninstalled Odoo 9.0-20160923 successfully from Program and Features and didn't uninstall the PostgreSql and then hard delete Odoo 9.0-20160923 directory from C:\Program Files (x86)\Odoo 9.0-20160923 too, Afterwards I successfully installed the Odoo 8.0 which only installs the Odoo files not the PostgreSql files now When i run the Openerp from browser it shows me the Internal Server Error as you may see in the attached image what is the actual problem Kindly suggest appropriate solution to this so i can manage to run this perfectly thankyou.
I resolved this issue by getting the PostgreSQL setup and runs the uninstall process which removes all the files then i un-install the Odoo 8.0 too then i made the fresh installation of Odoo 8.0 which then ask me to install the PostgreSQL database along with it now every thing is working fine. Actually issue was originated due to the missing PostgreSQL database as i didn't un-install it properly instead i hard deleted the entire Odoo 9.0-20160923 directory in which PostgreSQL database was located which cause it to damage.