How to mount a dirve in Knoppix 8.6.1

The PC that I currently have is running Kubuntu 16.04 and is now randomly freezing. Everything freezes except the mouse. A couple weeks prior to this starting all of the user data magically disappeared. Someone told me that I must have deleted it but I'm a little skeptical on that... Anyway, I want to check the current hard drive for possible sector corruptions and I was told the best way to do this is with a live OS or a USB flash drive with bootable software. So I downloaded Knoppix and used YUMI to create the bootable. I have tested the USB and everything works fine. Now I want to mount the drive as read only and check the drive for bad blocks. But I'm failing on finding clear instruction on mounting this drive as read only. I only want to scan the hard drive for possible sector corruptions and thats it. Can anyone provide some insight on my issue or suggest maybe a better way of scanning my hard drive for sector corruptions.

Thank you