If you want to install Odoo v12 in windows 7,8 and 10 follow the below mentioned steps:-
Step-1 Go to the link->"https://nightly.odoo.com/12.0/nightly/exe/
Step-2 Select->latest exe file like->odoo_12.0.latest.exe -> (Latest Date)
Step-3 click on Downloaded exe->select the languages->click on Next button
Step-4 select-> Odoo Server + PostgreSQL Database->click on Next button.
Step-5 Configure the information of PostgreSQL Database connection, Like..
(i) Host name- localhost
(ii) Port- 5432
(iii) Username- 'openpg'
(iv) Password- 'openpgpwd
(v) click on Next button
Step-6 click on Finish button
Step-7 Go to the browser ->http://localhost:8069
Step-8 In login window please enter the credential as follows `username:Openpg , password-admin
Step-9 Create Database and install Basic module. -