Please review the below excerpt from the Win96 Help File and see if that helps.
If the scanner does not begin sending data, or if Win96 displays an error message (e.g. Unable to open the COM port, timeout waiting for header, expected to read back data, etc.), you should attempt the following one at a time:
1. Double-check to ensure that you have the correct COM port selected.
2. Make sure the programming cable is firmly seated in the scanner’s jack and in the PC’s 9-pin connector.
3. Make sure that no other software is using the serial port. The usual suspects include PDA “sync” software, such as Palm’s HotSync. You must either close such software, or temporarily disable it (so that it’s no longer using the port).
4. Under Win96’s Configuration menu, select Serial Port…, and try each of the following:
a. If you’re using a USB adapter, try checking the Extra Write Time option.
b. If you’re using a home-built cable, try checking the Set RTS Line High option. If you’re using a GRE or Purple cable, make sure this item is not checked.
c. If you’re using a one-way cable, make sure the Enable “Readback” Tests item is not checked. (Note: a one-way cable cannot be used to download from the scanner; you can only upload to the scanner with this type of cable).
5. If no combination of the above helps, you should try another computer. There have been rare instances of serial port hardware that cannot drive the electronics in the interface cable.
