One of the most used personal computer interfaces for connecting other devices is the serial interface. Modern computers contain at most one serial port, while laptops do not have a single one, due to the robustness of the classic RS232 connector. Therefore, a popular solution for equipping a computer with a serial interface is a serial port to USB interface adapter.
This solution offers the flexibility of the electrical parameters of the serial input, output, compared to the standard RS232 interface, where the level of electrical signals ranges from -15V to +15V.
The assortment of adapters is huge as well as the number of chips used in them, development is constantly progressing, so it is very easy to meet a combination of a modern computer equipped with OS Windows11 with an older type of adapter fitted with one of the older chips, for example PL2303HX.
Although the adapter with such a chip is flawless, when connected to a computer with the Windows 11 operating system, drivers are automatically loaded from the Microsoft repository.
Since it is an older type and the development of drivers for new operating systems is finished, the new driver does not allow serial communication through such an adapter, and an attempt to open a serial port ends up with an error, in most cases with a message about insufficient permissions.
The solution to this problem is to use the older version of the driver 3.3.105, originally designed for older Windows XP, 7 and 8 systems.
All necessary files for "update" driver for PL2303HX chip can you find in the section download .