I have attempted to download the new optional update Windows8.1-KB3000850-x64 which is a large file. I have attempted twice from Windows update. Both times it downloads and seems to install fine. After I completes it asks for a reboot. During the reboot it gets to about 8% of install then it goes to another screen that states that, "Couldn't Complete the Updates Undoing Changes." It then restarts and boots up fine but the update is not installed. I also tried to download and install the standalone version and got the same error. I found a help article and tried it out and it didn't work. This is the steps I followed.Windows 8.1, Windows 8, Windows Server 2012 R2 or Windows Server 2012
- Open an elevated command prompt. To do this, swipe in from the right edge of the screen, and then tap Search. Or, if you are using a mouse, point to the lower-right corner of the screen, and then click Search. Type Command Prompt in the Search box, right-click Command Prompt, and then click Run as administrator. If you are prompted for an administrator password or for a confirmation, type the password, or click Allow.
- Type the following command, and then press Enter.
It may take several minutes for the command operation to be completed.DISM.exe /Online /Cleanup-image /RestorehealthImportant When you run this command, DISM uses Windows Update to provide the files that are required to fix corruptions. However, if your Windows Update client is already broken, use a running Windows installation as the repair source, or use a Windows side-by-side folder from a network share or from a removable media, such as the Windows DVD, as the source of the files. To do this, run the following command instead:DISM.exe /Online /Cleanup-Image /RestoreHealth /Source:C:\RepairSource\Windows /LimitAccessNote Replace the C:\RepairSource\Windows placeholder with the location of your repair source. For more information about using the DISM tool to repair Windows, reference Repair a Windows Image(http://technet.microsoft.com/en-us/library/hh824869.aspx).
- Close the command prompt, and then run Windows Update again.
Does anyone have any other ideas of what I might try?