It appears that the PC has automatically installed KB2919355 already earlier. You can check the installed updates history to confirm.
a. Press Windows logo key +X together, choose Programs and Features.
b. On the left side of the window, click on View installed updates link.
Check if KB2919355 is installed.
This error may appear for multiple reasons. Some common causes are VPN clients and an unexpected System Reserved Partition size.
Try removing any VPN Clients and attempt the update again.
You might be able to fix this problem by using third-party software to increase the size of the System Reserved partition.
As sfc /scannow command and it indicated that I have corrupted files, run the DISM tool.
Follow these steps:
a. 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.
b. Type the following commands. Press Enter after each command.Please note: It may take several minutes for each command operation to be completed. Please do not cancel it.