The Sharp Willcom D4 is an Ultra mobile PC (UMPC) made and sold only in Japan.
It is capable of running Windows 8 with the touch-friendly Metro-UI. All of the components are supported in Win8. Due to the default partitioning the device will run out of disk space on the system partition if the users installs all recommended Windows Vista and Microsoft Office updates even if no other software was ever installed. Sharp support advised users to change the partitioning by removing or at least reducing the size of the second visible (data) partition. The recovery partition is recommended to be kept for disaster recovery although such recovery will result in the original problem the system partition being too small. The case is rubberized with a chemical process which originally gave it a nice haptic feel and good grip. However now that more than a decade has passed the rubberized coat has decayed into a sticky mass which makes it unpleasant to touch the device. The sticky chemical resi