If a Repair Install doesn't work, it might be easier to just reinstall your system from scratch, starting with Windows 7 SP1, and then update from that point forward.
Download the correct ISO here: Official Windows 7 SP1 ISO from Digital River « My Digital Life
Burn it to a bootable USB drive using this tool: Microsoft Store Online
Install it and format your drive at the same time. Validate it during install with your licence key, then immediately run Windows Update.
Post back if you have any further trouble.