Ok, so you were installing Win7 on a Win7 drive?
That's why it flipped over into Repair mode.
And since your parts have changes there are probably driver issues.
Use the Custom (Advanced) install option for a clean install. You could also partition the hard drive from that option, shrink the primary partition, create another and install Windows into that new partition. That would leave your files intact even though the games won't run unless the original install of Windows gets repaired.