If you have some old battery operated toys lying around then you're in luck.
We're going to need a dc motor from the old toy, A scissor and your USB modem of course.
Unwound the copper wire from the dc motor, then wound about 15 to 20 loops around your USB modem preferably near the tip or where the internal antenna might be. Then secure the copper wire, you can knot the ends or tape it in place. Then plug it to your computer see the improvement on the reception.