Has the bobbin winder worked in the past and now faulting. Or are you unsure on how to use it?
There is a manual for a Touchtronic 2000 here http://www.singerco.com/uploads/download/432_touchtronic.pdf
there may be more than one model Touch Tronic so plse check the serial number plate on the side of your machine to establish the actual model number, usually near the power inlet plug. then search for the appropriate manual at http://www.singerco.com/accessories/instruction-manuals
. This excerpt shows that you wind the bobbin insitu in the bobbin case.
I'm not a fan of prewound bobbins, far better to deal with the bobbin winder issue. Winding your own thread means you can get far better colour matching to the fabric, and ensure you've got quality thread on the machine, and same thread top and bottom. (I prefer a quality cotton wrapped polyester or a polyester thread, Guttermann, Molynecke or Sylko Supreme). All of these factors affect stitching quality and the finished appearance of a seam.
Did you know that you can buy a freestanding unit to wind bobbins? Link to this item is here. http://www.sewingpartsonline.com/universal-automatic-bobbin-winder.aspx
You may well find that this is the better solution to winding bobbins for this machine as winding them inside the bobbin housing doesn't give you a lot of control over the way the thread feeds onto the bobbin.