From the January 11, 2015 the problem to install the driver ARS-USB in Windows 8 – because the driver was not signed – is already solved.
You no longer need more Disabling Driver Signature, as you had to do until now and explained in the FAQs:
Microchip – microcontroller manufacturer – now provides a signed driver for a number of VID & PID. So we changed the VID & PID we used till now (VID: 04D8 & PID: F8E7) to one that is included in the new driver of Microchip (VID: 04D8 & PID: 000A).
Therefore, from the version of ARS-USB V2.3A will use the new driver provided by Microchip.
Users who want to continue using previous versions to V2.3A have to use the driver (not signed) that came before.
All these versions of the driver and firmware ARS-USB are available in the download area: