Check Disk.

Is there any need to run Check Disk (chkdsk) in read-only mode?

 

It might be a good idea when you suspect physical sector/file system damage; allowing writes ('fixes') could turn a damaged sector into a freshly reallocated one from the super-hidden section of the drive, resulting in a file with a 'hole' in it. If that file is something vital for your software or Windows, the next boot, or the next time you try to start the affected software, might be tricky or result in a failure.