And one man has answered:
Adding and removing that checkmark makes Binary Data changes in the
following Key:
HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\User Preferences
"6256FFB019F8FDFBD36745B06F4540E9AEAF222A25"
Type: REG_BINARY

The problem: I have tried it but without success because i have done the changes then i have exported the key in the registry editor. But when i wanted to double click on the key exported, it tells me:
Can not import C:\...
"Not all data was successfully written to the registry. Some keys are open by the system or other processes"

Would anyone please to tell how to fix it? Thanks