Probao sam sa clear install opet isto.Pa verovatno hoćeš stariju verziju preko nove.
Tako jedino Clean Install ili nabavi najnoviju instalaciju. Clean install briše sve podatke i programe.
http://www.sevenforums.com/tutorials/1649-clean-install-windows-7-a.html
https://www.tenforums.com/tutorials/1950-windows-10-clean-install.html