The storage of binary information in twistor wire is complicated by the presence of demagnetizing fieldsresulting from the open flux path structure of this device. These fields modify the writing threshold of eachbit and contribute an interaction with neighboring bits on the same wire. The effect of these demagnetizingfields has been measured with a search-coil technique. A simple procedure consisting of a coincident-currentbit select followed by a single-current read select is used to form and “erase” the magnetized regions. It isfound that the shape of the magnetized regions thus formed are a complex function of the two currents usedand that the bits are not fully erased by the single current. The results suggest that demagnetization mustbe reduced by reducing thickness and/or bit density unless a more complex solenoid structure can be foundto control the magnetization of the bit regions.