Asasam Dongle Problem - Not Reconized!

please help me:
I spent yesterday trying to get the dongle to work properly
in 2 different computers. The dongle will become recognized
then unrecognized by the computer (you can see the light in
the dongle flash on and off). However even when it is bein
g recognized by the computer whenever trying to unlock / roo
t /repair phones it gives error messages . So basically the
dongle is recognized sometimes by the computers and even th
en it still doesnt do what it is supposed to do.
it's a new dongle, what can i do to solve the problem?
thank you!