问题
解决:
1.手动安装了 Windows8.1-KB2919442-x64
2.手动下载 KB2919355
更新成功
Turns out to have been a result of a USB Restriction GPO which locked down permissions to USBSTOR.sys, which KB2919355 has to update, and fails if it can't. Once we remediated the policy on the machine and restored the correct permissions to the file, the update went through just fine.