Windows Defender block - How to unblock - Microsoft Community

i have uninstalled agv antivirus , zen program because blocking me running other programs windows defender , mozilla firefox browser.      i have made sure can find connected avg off of computer, problems continue. 

when trying activate windows defender receive message saying , more information contact system administrator.  (error code: 0x800704ec)    

similar code when try re-install  mozilla firefox browser; uninstalled because thought malfunctioning.  i realize not move.   error code receive when try re-install is::>   current security settings not allow file downloaded.    <

there third problem odd.  when on administrator profile on computer can not see when go facebook.  the headings there none of log in things nore pictures on page.  when go anywhere else, can , if on personl profile on computer can see facebook in browsers.    

can me these problems?   considering wiping computer , re-installing full up.   
ever much.  
rain 

***post moved moderator appropriate forum category.***

hi rain,

it seems you're having issues running windows defender on windows 7 pc. let's try resolve error code 0x800704ec following resolutions posted tom_ec on this thread , arthur li on thread.

note: section, method, or task contains steps tell how modify registry. however, serious problems might occur if modify registry incorrectly. then, can restore registry if problem occurs. more information how , restore registry, refer following microsoft knowledge base article.

how , restore registry in windows: https://support.microsoft.com/en-us/kb/322756.

keep posted , we'll wiling assist further.

Windows / Windows 7 / Security & privacy