A+: Common Disc Problems
Disk access time increases
Files are fragmented, split among many locations on the disc.
Defragment the file structure with the Windows Defrag utility or other defragmentation app.
Data files are deleted, need replacement
Caused by user error, malware, defective software.
Restore from a previously tested backup (you ARE backing up regularly, and testing the backups, right?)
Disc errors cause less reliable operation
Shutdown not performed properly, program error or drive failure.
Run CHKDSK to test drive for errors, make sure you are using the latest version of the app and of Windows, test the drive with a diagnostic and migrate to a new drive if required.
Disc drive errors confirmed
File system errors.
Back up data one last time then do a full reformat. All existing data will be erased.
Hard drive connected, but can't be accessed
Drive not partitioned.
Prepare drive with Disk Management.