This problem can occur when the device EEPROM is set to use D2XX drivers and the user is attempting to install using the combined FTC drivers for D2XX and VCP for Windows 2000 and Windows XP. The combined drivers will only provide VCP functionality under Windows 98 and will always install an FT2232C device with VCP drivers.
To install a FT2232C device configured to use D2XX drivers under Windows 98, the FTCD2XX drivers must be used. This driver release will provide D2XX drivers for Windows 98 and will also install D2XX devices under Windows 2000 and Windows XP.