Product Name: Compaq Presario CQ5207SC
Operating System: Microsoft Windows 7 (64-bit)
I need help to install an operating system on my old desktop. It didn't run Windows 10 very good so I tried to degrade it back to Windows 7. Apparently it failed, and had also somehow deleted the Windows 10 operating system. So now I'm left with no installation disc (I lost it), and no operating system. Where can I get the OS, and how? Also, how can I boot the installation from CD or flash-drive? Tell me if you need serial number, product key etc.
Thanks in advance