Error 0xC1900101-0x30018 with Windows 8.1 Update

users are having problems with the error code 0xC1900101 - 0x30018 when installing Windows 8.1. This error is typically caused by an incompatible driver. So make sure that you have already updated all of your drivers.

I've read somewhere that the error has been solved after running the Upgrade Assistant utility from Microsoft. It scans your PC and connected devices and then provides a compatibility report from which you can find useful suggestion to get the update successfully. For example the Upgrade Assistant can identify available important updates to drivers.
Here is the link for it:

Some users by disabling WiFi card in BIOS now can update to Windows 8.1 successfully. You can try it, just go to BIOS Setup, find the Wi-Fi card (something like "Integrated WLAN"), disable it, save changes and restart. When reboot, try to update again. If the BIOS does not have any option to do that, so you have to physically remove your WiFi card.

Another possibility is that some software is currently not supported on Windows 8.1 and it caused the problem. In many cases, users have SteelSeries products that support the SteelSeries Engine installed on their PC. The SteelSeries Engine software is currently not supported on Windows 8.1. Some other software is anti-virus or PC performance utilities like TuneUp Utility or 3rd party Start Menu apps like IOBit, Samsung Quick Starter or Magic Iso/Magic Disc, Deamon Tools .... So uninstall the software before attempting to update to Windows 8.1 also help to resolve the issue.