I used tweaking in hopes of repairing a windows update failure problem. For months now, all updates have failed except Windows Defender, they all download and install with no problem. I have attempted to do everything I can find to fix this problem but nothing works. I had updates set to automatic but when I was unable to download win 8.1 I found all updates had failed since last july. I have 54 pending. When I try to download either automatically or manually, they fail. I get error messages of 8007045B or 80071A91. The win 8.1 failure is caused due to lack of update KB2871389. I have it listed as one of my updated files, but since it fails to install, win 8.1 will not install. Each time I try to download and Install, the download gets to 11% and fails. Any help anyone can give will be greatly accepted.