Windows 7 premium will not boot up

[aliciaj12]

bought a pc that someone tried to upgrade it to ultimate we tried putting back on premium now just get blue screen after installation failed tried to run again now won't start up at all

 

[jsmakkar]

Are you able to enter BIOS.
I would suggest formatting of HDD before installation of Windows. During installation process, an option is presented to format the HDD.