After encountering problems with installing the Spring Update (KB2919355) myself, I think I may have finally resolved the issue. First, here's the common fixes everyone should try: - Disable any Anti-Virus, Anti-Malware, or Internet Security Suites you may have installed. - Make sure you have the pre-req of KB2919442 (you can download it separately from Microsoft Download Center). - Try downloading KB2919355 manually. You can google "KB2919355" and "download" and you'll eventually get to the right place on Microsoft Download Center. It's actually a collection of multiple packages, of which "KB2919355" should be installed first. See the spoiler below for which order to install these packages in: Spoiler 2919442 2919355 (reboot) 2932046 2937592 2938439 (reboot) 2934018 (reboot) - thanks to murphy78 - Try running the Windows Update Diagnostic Tool, which you can get from googling "Windows Update Diagnostic" (it's a FixIt tool). You may have to run it multiple times, rebooting after each. - Try running the System File Checker in Safe Mode on a command prompt, rebooting after: Code: sfc /scannow - Try running the CheckHealth and RestoreHealth DISM commands on an Administrator-level command prompt, rebooting after: Code: dism /online /cleanup-image /checkhealth dism /online /cleanup-image /restorehealth And finally, if nothing else works, the command which I think fixed it for me: Code: dism /online /remove-package /packagename:Package_for_KB2919355~31bf3856ad364e35~amd64~~126.96.36.199 dism /online /cleanup-image /startcomponentcleanup ..and then immediately try running the offline/standalone version you downloaded earlier. Note that this is after I tried doing "DISM /online /get-packages /format:table | findstr KB2919355" and got no results, so probably KB2919355 was stuck in some half-installed state.