Many versions of this driver are not digitally signed by Microsoft. Modern Windows versions (7, 8, 10, and 11) will block them by default. Go to > Update & Security > Recovery . Under Advanced startup , click Restart now .
: Install the SCI USB2Serial drivers on your Windows PC.
You will see an unknown device, likely named "SCI USB2Serial" or a generic "Spreadtrum phone" with a yellow triangle, under "Ports (COM & LPT)" or "Other Devices". spreadtrum sci usb2serial ok
The driver acts as a bridge between your computer's USB port and the serial interface used by the Spreadtrum processor . When a device is connected in "Flash Mode" (often by holding specific volume keys while plugging in), the computer identifies it as a . Key Use Cases
Windows may have automatically assigned a generic USB-to-Serial driver instead of the proprietary Spreadtrum driver required for flashing commands. Many versions of this driver are not digitally
The Spreadtrum SCI USB2Serial is a deceptively complex diagnostic multiplexer, not a simple serial adapter. Its packet-based framing, channel mux, and security quirks make it both powerful for engineering and risky if left enabled in production. Understanding its protocol allows building custom diagnostic tools, performing deep mobile forensics, or even discovering baseband vulnerabilities. For driver developers, it’s a case study in why CDC-ACM is insufficient for vendor-specific multiplexed transports.
However, many users face issues where the driver does not install correctly, leading to flashing tool errors, "device not found" messages, or the device constantly disconnecting. Under Advanced startup , click Restart now
Click in the top menu bar, then select Add legacy hardware .
Click , then OK . Select the appropriate interface name from the list (e.g., SPD SCI Diag or Spreadtrum COM Port ) and click Next .
