[32-bit WIN 7] directly install CH341SER.EXE download address: /download/list.asp? Id=65 If prompted: "The service installation paragraph in this INF is invalid". Download "serenum.sys" on the Internet or search (including system files and hidden files) serenum.sys under drive C, and then copy it to C:\WINDOWS\system32\drivers and reinstall the CH341 driver. [64-bit WIN 7] Manually specify the installation directory to install CH341SER.ZIP Download address: /download/list.asp? Id=5 Every time the boot system is started, you need to press F8 to select the mode of "Disable driver signature enforcement". After finding the corresponding hardware in the device manager, select update driver, and then manually specify the installation directory for installation. You should select "Continue installation" in the pop-up warning dialog box. We are applying for digital signature and will update the driver later.