I just installed desktop 15 on a newly formatted Windows 10, 64 bit Dell Optiplex 980 machine. No problem. Try to repeat installation on a newly formatted Windows 10, 64 bit Dell laptop, and license key fails. Also, the dialog keeps reformatting the position of the dashes in the license key. Tried retyping multiple times, and restarting.
This is a corporate environment with standard disk images.
p.s. the laptop is in a docking station with external keyboard. Could that be a problem?
Update: it IS the docking station. When we took the laptop out and installed without external keyboard, it worked fine.