Yesterday, I changed my OS from Windows8 Pro to Windows8.1 Pro on NJ2100. By the way, NJ2100 is an Epson Direct product in Japan. But, I think an ASUS product X51C and this are the same in specs.
First I backed up my Win8 Pro by AOMEI Backupper.
Second, I accessed the Store from the Metro UI and tried to update.
The downloading maybe takes several hours, of course, though it depends on the environment.
When ending the downloading, it shows us the reboot message. So, reboot the PC.
I had no problem until this point. However, even after several hours, the installation did not end, the monitor displayed nothing and the HDD indicator never lighted up. I gave it up, and turned off the PC. When I turned it on, the PC restored Windows8 Pro and gave me an error code “0xC1900101 – 0x30018”. According to information on the Internet, the error seems to happen the PC has driver(s) which is older than Windows8.1 Pro requires. As my six sense told me the driver was the driver for “SiS Mirage 3 Graphics” (^_^;), I removed it and tried again.
This time, I reached the goal. I tried to use the Windows8.1 Pro. The monitor resolution was 1024×768, so I installed the driver for “SiS Mirage 3 Graphics” again. But after that, I had a lot of freezes. Besides, I felt the High Definition Audio driver version 18.104.22.16806 did not work well, either. These two drivers are very necessary for comfortable using NJ2100. I can still use my Windows8 Pro. So, I decided that I kept my Windows8 Pro until updating to Windows8.1 Pro was absolutely required.
I backed up the new Windows8.1 Pro because I didn’t want to waste my time again, and restored the old Windows8 Pro to my NJ2100.