Avast Cleanup says c: drive is healthy but actually has a lot of bad sectors. As a result, I was misled, kept using the drive until it crashed. I was unable to backup my lastest data.
I don’t believe that the Avast Cleanup product is actually checking for bad sectors - https://support.avast.com/en-gb/article/cleanup-premium-faq/#pc
I don’t use Avast Cleanup and I don’t work for Avast, so I can’t speak from personal experience.