By default this option is enabled,but on some systems it is not, so below is the information on how to turn it on:
Go to Start Menu and Click RunType in regedit then click okFind "HKEY_LOCAL_MACHINESOFTWAREMicrosoftDfrgBootOpt imizeFunction" Select "Enable" from the list on the rightRight on it and select "Modify"Change the value to Y . Reboot your Pc and see the change yourself.