Security Device

I am still trying to get my V6 to work. Message appears "Security Device not found Restart Software.
Today I took the computer to Micro Soft and the software opened with my dongle with no problem.
Returned home, reconnected wires, and software would not work.
Returned to Micro Soft with computer and dongle and it worked again.
Brought it back home and again, it does not open.
We are baffled. Why does it work at the business and not at my home???
Same computer and dongle.