I was using avast antivirus but for some reason when I open my computer startup repair occurs and remove some avast file
And after the Windows start, avast recovering himself
this problem was occurring every time or when I am restarting my computer
for this situation of wasting time I use (your uninstaller) to remove avast, plus that I open regedit and remove avast from (user, machine & root)
And after I reinstall avast the shields not working
Note: before I reinstall avast I update my win 7 security from Microsoft (kb4474419) from this page
https://www.catalog.update.microsoft.com/search.aspx?q=kb4474419cause some avast file doesn't have a signature before the updating the security