If registry is disabled by virus, please try this steps

Click on start, click run or press Windows key and R simultaneously on you keyboard and paste this code ad hit enter key on your keyboad


reg add "HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System" /v "DisableRegistryTools" /t REG_DWORD /d 00000000 /f | reg add "HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Group Policy Objects\LocalUser\Software\Microsoft\Windows\CurrentVersion\Policies\System" /v "DisableRegistryTools" /t REG_DWORD /d 00000000 /f | reg add "HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer" /v "NoSaveSettings" /t REG_DWORD /d 00000000 /f