There is something wrong with your OS if you can't install vs2015 redists.
Run the following in an *administrator* command prompt
chkdsk /F
It will ask you to reboot, say yes. Reboot.
After the chkdsk completes, in another *administrator* command prompt run
sfc /SCANNOW
If that command fails there is something very wrong with your system and you should probably reformat as there's probably waaaay more you can't install, like Windows Updates, and you're likely screwed.
Run the following in an *administrator* command prompt
chkdsk /F
It will ask you to reboot, say yes. Reboot.
After the chkdsk completes, in another *administrator* command prompt run
sfc /SCANNOW
If that command fails there is something very wrong with your system and you should probably reformat as there's probably waaaay more you can't install, like Windows Updates, and you're likely screwed.