25 What command should you run to check and fix corrupt system files, DLLs, and other critical files? A cmdcons/fixboot B defrag-a. C chkdsk /r D sfc/scannow 26 Which feature in Windows 7 enables you to right-click a file or folder and restore previous versions of that file or folder? A Undelete. B Reversion. C System Protection. D System Revert 27 How frequently does Windows 7 make an automatic backup of the Registry? A Once a day B Never. Once every 30 days D Once every 10 days