Standard Upgrade Failure troubleshooting steps
Make sure the PC passes the compatibility check.
Make sure there is at least 16 GB Free Space on the OS drive. See here if you get "we couldn't update the system reserved partition"
Make sure all drivers are updated, especially the Video driver.
Peripheral drivers are also one of the common reason for upgrade failures. Disconnect everything except Keyboard, Mouse, and display.
Correct drive corruption on C: drive (Reference)
https://www.yourwindowsguide.com/2018/04/how-to...
Disable/Uninstall Security Software
Ensure BIOS is updated.
Try installing the feature update in Clean Boot mode (How to perform a clean boot in Windows.)
https://support.microsoft.com/kb/929135
Remove the unnecessary features in Windows you do not use, like IIS which is a common cause. See this tutorial here.
Make sure to install the latest cumulative updates before.
The most important step in this is putting the PC to clean boot, disconnect unnecessary devices and then try again. Running a chkdsk on boot drive is also not a bad idea. You may post the CHKDSK logs for us to check..