You can determine whether your file system errors are legitimate.
To know if you've got a file system error, you can type the following command at the command prompt:
fsutil dirty query c: (replace c: with your drive letter)
If the response is that the volume is dirty, then a file system error has occurred, and Chkdsk should run automatically at startup to fix the errors.
The drive manufacturer will have free diagnostic software to thoroughly check the condition of your hard drive in case that is failing.
If you are regularly inside the computer box, a loose connection may be the cause?