It can't detect what is wrong with your system - it can only run the repairs that you select.
Windows has its own tools for doing that which are -
chkdsk /f
chkdsk /r
sfc /scannow
For Win 8 and above - dism /online /cleanup-image /restorehealth
You would normally run that command first and then run a sfc /scannow to confirm there was no system corruption.
However, a sfc /scannow can't fix all problems and a Google will usually bring up links either for a MS fix or links that include solutions that have worked for some.
In extreme cases, a repair install may be the only answer.