Do not use the command
'chkdsk /f /r c:' .

Use either
chkdsk /f c: or
chkdsk /r c: Don't combine both those switches together.

On modern disk drives,
chkdsk /r c: implies the "/f" switch anyway, so it's an uneccessary duplication. Check out this link to explain the switches:
Command Line Check Disk Options, Switches, Parameters
It would also be helpful to know the Make/Model of the hard drive you are attempting to run this command on. And whether it's a
HDD, SSHD, or
SSD drive type. Once you know that information you can run further manufacturer drive diagnostics by visiting this link:
Link Removed
When asking for help with this particular command which...