Cause: COM port number too high (e.g., COM20).
Fix:
This is the most reliable method if an auto-installer is not present.
Ignore the "Driver not signed" warning. Click "Install anyway." coolsand rda usb driver 32 bit
If you are reading this, you likely have a small pile of old Chinese feature phones (Spreadtrum or Coolsand based), a vintage RDA5868 development board, or you are trying to flash a firmware backup to revive a "dead" device from 2012.
Welcome to the club. The Coolsand (now part of RDA) USB driver is notoriously finicky. While everyone else has moved to 64-bit Windows 10/11, we need to take a step back in time to the era of 32-bit computing. Cause: COM port number too high (e
Here is everything you need to know to get that yellow exclamation mark to disappear.
You will encounter the need for the 32-bit USB driver if you own or repair devices such as: This is the most reliable method if an
When downloading "coolsand rda usb driver 32 bit," look for a package containing the following critical files:
| File Name | Purpose |
|-----------|---------|
| RDA_USB_Driver.inf | Setup information file that tells Windows how to install the driver. |
| RDA_USB_Driver.sys | The actual kernel-mode driver binary (32-bit). |
| RDA_USB_Driver.cat | Catalog file (often omitted or self-signed). |
| Install.bat or DPInst.exe | Optional installer helper. |
| usbser.sys | Sometimes included as a substitute if Windows lacks native serial drivers. |
If you cannot get the 32-bit driver to work, consider these options: