I bought
LIVA-64Gb (ECS), which was the world's smallest windows PC. It is very funny but powerful more than I imagined.
At first, I installed windows 8.1 easily. Some original drivers must be installed manually.
The LIVA's case is so stiff that re-opening is not easy. Therefore, I scraped some holding pins smoothly.
I feel that Wifi often disconnects when USB3.0 is used. To attach a extension cable for USB3.0 may improve that phenomenon.