But the update would hang in the middle and I would need to restart the PC after sometime.
Windows Update would download the updates successfully and start installing the updates after restart. Things went smooth until the next upgrades of Windows 10 build 10041 and build 10049. The same products key of Windows 8.1 was used for Windows 10 upgrade. I didn’t have to enter a new product key for Windows 10. The upgrade went quite smoothly and there was no issues during or even after the upgrade. If that doesn’t work, we can run System File Checker and Deployment Imaging and Servicing Management to verify the integrity of your existing Windows install.I recently upgraded my work laptop from Windows 8.1 to Windows 10 build 9926. Perform a final Windows Update before the install so you have everything up to date.Update all of your graphics, audio, network and motherboard drivers.If you use Daemon tools or other drive simulator, stop the service.Uninstall anything that locks files, for example Spybot, Adaware or any encryption software.Uninstall your firewall, antivirus and any malware detection software you have installed.If you’re not comfortable reading log files, we can use the broad brush approach and address the most common issues that cause 0xc1900101 installation errors. Find out what is stopping the install, address it by uninstalling, disabling or updating and retry the installation.
This should tell you exactly what is causing the issue.