On some systems i have found "everyone" with full control of HKCR, it seems to me that this setting is incorrect and a security issue. In fact some support pages showing solutions just like this: Highlight the Everyone group by clicking on it Check in "Full Control" if it isn't checked in Check in "Read" if it isn't checked in. Highlight the Administrator group by clicking on it Check in "Full Control" if it isn't checked in. Check in "Read" if it isn't checked in. Click the Advanced Button Check in the box "Replace permission entries on all child objects with entries shown here that apply to child objects" Click Apply Have someone in the community, a similar experience and even seen such causes? Are there some programs known that were cause this?