Xhorse VVDIProg “unable to find equipment” solution

Problem:
One of Xhorse VVDI Prog programmer user tried to update software to latest V4.4.2. But he failed to update it and VVDI-Prog prompted error message: “unable to find equipment”

vvdi-prog-programmer

Possible reason:
1. VVDIProg programmer has not been connected well.
2. VVDI Driver has not been installed well/completely.