It probably is the corrupt files that is preventing Windows Repair from opening but see if it works in Safe Mode with Networking by tapping F8 (usually) as you switch on and use the cursor keys to select that option.
You could also perform another sfc /scannow and when it reports it is unable to repair all, download and run SFCFix.exe -
https://www.sysnative.com/forums/downloads/sfcfix/Read through the article for an explanation in how to use it.
You could upgrade to Win 10 or if you have a Win 7 Pro install disk with a valid retail key then you could perform a repair install which doesn't affect personal stuff or installed programs.
Not so long ago a member posted that you could still get Win 10 free through the MCT update at
https://www.microsoft.com/en-gb/software-download/windows10Win 10 digitally activates so you don't need a product key if it will install.
See what the Update Now button gives you, but it may be best to create a system image first and a system repair disk to recover from that if you don't have a Win 7 Pro install disk.