"Chkdsk" is a Windows utility used to check your hard drive for corrupted partitions. The chkdsk utility attempts to fix any problems and reallocate space by locating and blocking the bad hard drive sections and sending information to a good section. You can run the "/r" switch to automatically fix sections where Windows is able to repair the hard drive issue. If you don't use the "R" switch, the chkdsk utility does nothing more than report bad hard drive sections.
Click the Windows "Start" button and select "Run." If you are using Windows 7 or Vista, enter "cmd" into the text box displayed when you click "Start." Other Windows users should type "cmd" into the "Run" text box and press "Enter." This opens the Windows command line.
Type "chkdsk /?" to view all chkdsk options. Review the options, because you can use other switches with the "/r" option.
Type "chkdsk /r" into the command line and press "Enter." The Windows system performs several initial checks, but then it does a complete check of the hard drive. It may take several minutes for the utility to complete the check.