I last updated windows defender on 9/11 and the definition version is 1.43.309.0 so I tried to update it today, and got an error code. The error code is 0x80070643, so I tried to manually install updates, and ran into another problem.

When I try to check for updates:


Here's what happens when I try to manually install updates:


Any ideas as to fixing this problem? And please ignore the mac os x look in the screenshots, it's just a theme I have for my computer. Thanks [=