Can't turn on file and printer sharing (save didn't work) windows 7

Today i've got a problem, i can't change my file and printer settings (i saved the setting and after i view back it doesn't change old settings):

• i can't share folder and printer settings (Control Panel\Network and Internet\Network and Sharing Center\Advanced sharing settings)
• i can't view devices and printers (Control Panel\Hardware and Sound\Devices and Printers)

My OS is Windows 7 Ultimate, i remember that in the morning my laptop was crash and reboot automatically.

After searching in some forums and google, i found this command:
SFC /SCANNOW
Run as administartor > wait the process to finish > restart your computer > done.
I can share my folder and printer again, and i can access view devices and printers again.
Thx to google and people in that forum.


The description of "sfc" command:
Scans the integrity of all protected system files and replaces incorrect versions with correct Microsoft versions. <-- COOL!!!

/SCANNOW:       
Scans integrity of all protected system files and repairs files with problems when possible.

Some links:
http://www.sevenforums.com/tutorials/1538-sfc-scannow-command-system-file-checker.html