sfc/ scannow stops at 68%

Hi everyone, Sorry to disturb you but I read all the topic and I have some problem with the comand sfc/ scannow when I run it, it stops at 68% My first intention was only to check my system files because my Windows Intaller doesn't work anymore and it tells me that my msi.dll file is dammaged (so I can't install open office or java anymore...) But when I run sfc / verifyonly it tells me...