I too am having difficulty on a Windows 7 x64 system. The software installed fine, but it does not see Joulescope . When Joulescope was connected, it went through the automated driver installation, but did not show up in the device manager as Joulescope . It did show up as an anonymous USB device.
I think the problem is that there are multiple versions of WinUsb in the wild, and Joulescope might not work with all of them. I have seen this with the low-end logic analyzers from Saleae. Saleae 8 channel analyzer works with V6.0.6000.16388 but not V6.1.7600.16385 Part of the problem with tracking something like this down on Windows, is that it installs the driver separately for each physical port.
I installed the software on another W7 x64 system and initially Joulescope didn’t work there either. I then tried other USB ports, and on the third try, the software recognized Joulescope and the software worked, so I know the Joulescope hardware is ok (except maybe the way it reports its USB information? to the system which might effect how drivers are loaded???).
There is a program called Zadig that supposedly lets you change which driver is applied for a given device. I am not sure if this helps, or muddies the water more, as you can only choose from its list of built-in USB drivers, which include V6.1.7600.16385 but not V6.0.6000.16388.
Anyway, I feel I can do more research, and in particular, try and characterize the full information from the device manager for both working and non-working scenarios.