Have you by chance looked at the resulting CBS log file to see what is exactly the problem that cannot seem to be fixed by the Safety Scanner?
The cannot be repaired result is typically returned after a scan if your system is infected with virus or malicious code of some sort.
Have you any anti-virus software installed and are you receiving an infection result from the your scans of your using it? You must also remember that pirated software installations can also corrupt system files. Check your system for anything like that which you may need to remove before trying the scan again.
Otherwise, you will need to run the safety scanner offline and repair any corruptions using the Deployment Image Servicing and Management (DISM.exe) utility to repair or replace any corrupted system files back to their original pristine state.
Using the same Command Prompt window that you use to run the Safety scanner, also run the Deployment Image Servicing and Management (DISM.exe) as an Administrator with elevated permissions.
Simply type the following once the SFC Scanner concludes its scan and returns to you its could not repair result:
"DISM /Online /Cleanup-Image /ScanHealth" and follow that once the scan completes and returns to you its result with "DISM /Online /Cleanup-Image /RestoreHealth," minus the added quotation marks of course.
Depending on the result you get from both the CBS log and the DISM log, whatever corruption you may find may be fixable using these two tools. Otherwise you may need to uninstall the offending items causing the corruptions first, before these tools will be able to effect repairs of your system files.
My bad.... Sorry! I spent a great deal of wasted time on this issue for myself, so I just thought many could benefit from that time I invested in getting answers to this very wide-spread problem with Windows users. Albeit, Microsoft is terrible at explaining these things to their users. And their technical support is even worse at actually being able to help with an issue that cannot be fixed accept by migrating away from the users current version of windows to the next upcoming version.
I guess it would be kind of difficult to have to explain why they have installed updates that cause issues either real or imagined for which the only fix for is to upgrade to a new untested version of their product.
We just couldn't make this stuff up even if we tried.