Might want to see which BIOS version you're currently on for your motherboard.
To be very blunt, that platform is so old, that it doesn't officially support Windows 7. Even if you did get to install the drivers for the system in compatibility mode, you're going to have to pass the hurdle of the system being unstable. That would lead me to guess that there's something wrong with your installer.
Mind if I ask you where you sourced the installer for Windows 7 and which version you're working with?
+ Welcome to the forums, newcomer!