I tried to install Windows 10 TP x64 Build 9926 onto my ThinkPad X230 which is set to UEFI only from a USB3.0 USB stick connected to the USB3.0 port. But an error message titled "Load driver" and saying "A media driver your computer needs is missing. This could be a DVD, USB or Hard disk driver." appeared and I could not proceed.
To narrow down the cause, I did the following:
- I checked the hash code of ISO, English (United States) version of Windows 10 TP x64 Build 9926, which I used for making the UEFI bootable USB3.0 USB stick. It was the same as the value specified in the download page. So ISO seems okay.
- I downloaded Japanese version ISO, checked the hash code and tried to install in the same way. I faced an error message in Japanese equivalent to English one. So language version does not matter.
- I burnt the ISO to DVD-R and tried to install from USB2.0 DVD drive. This time, the installation completed. So ISO itself is okay.
- ThinkPad X230 has two USB3.0 ports and one USB2.0 port. I inserted the USB3.0 stick to one of USB3.0 ports (so they communicate by USB3.0) until then. I changed to another USB3.0 port but no change. Then I changed to USB2.0 port (so they communicate by USB2.0) and finally the error message did not show up and succeeded the installation. So whether USB3.0 or USB2.0 seems to make the difference.
- I tested another two USB3.0 sticks of different brands and confirmed that when they were connected to a USB3.0 port, the same error happened and when connected to a USB2.0 port, no error. So it is not caused by hardware failure of a USB stick.
- I tested a USB2.0 stick and did the same thing with all three ports (so they communicate by USB2.0) and the installation completed without the error. So this issue seems not to happen when connected by USB2.0.
- I downloaded Windows 8.1 x64 enterprise evaluation ISO and did the same thing. The installation completed even when the USB3.0 stick is connected to a USB3.0 port. So this issue seems to be specific for Windows 10 TP.
- I heard some other people experienced the same problem with their ThinkPad X1 Carbon. So it is not limited to my ThinkPad X230.
In conclusion, I think there might be something wrong in USB3.0 support of Windows 10 TP installation ISO.