In the dimly lit basement of a tech enthusiast’s home, there was an old, dusty smartwatch. This wasn’t a high-end device from a famous brand; it was a generic, budget-friendly gadget powered by the MT6261 chipset. For years, it sat in a drawer, its screen dark and its purpose forgotten.

| Mode | Function | Driver Type | |------|----------|--------------| | Download / Preloader | Device is off or resetting; enters boot ROM mode for flashing. | MediaTek DA USB VCOM Port or Preloader USB VCOM | | AT/Modem Mode | Device is booted normally; provides AT command interface or modem logs. | MediaTek USB Modem Port, often enumerated as COM port (e.g., COM3, COM5) |

Select the .inf file (usually found in a subfolder named Win10 or CDC).

Step 2: Install the Driver via Device Manager (Manual Method)

1. Turn off your MT6261 device. Remove and re-insert the battery (if removable).
2. Do NOT plug it into the PC yet.
3. Open Device Manager (Right-click Start button → Device Manager).
4. Click Action > Add legacy hardware > Next.
5. Select Install the hardware that I manually select from a list (Advanced).
6. Choose Ports (COM & LPT) > Next.
7. Click Have Disk > Browse.
8. Navigate to your extracted MT6261 driver folder and select the .inf file (e.g., mtk_usb_com.inf or MediaTek inc_1.0.0.0.inf).
9. Select MediaTek USB Port or MediaTek DA USB VCOM Port from the list.
10. Click Next > Install.

6. Common VID/PID and identification

• Devices use Vendor ID (VID) and Product ID (PID) assigned to the manufacturer. Bootloader or flashing modes often use different PIDs than normal operation (e.g., one PID for normal CDC, another for bootloader).
• Identify device via lsusb (Linux) or Device Manager (Windows) and check descriptors to determine current mode.

5. Step-by-Step Installation (Windows 10/11)

Modern Windows often blocks unsigned drivers. Follow carefully:

6. Recommendation for Developers

• Always use the latest MediaTek official signed drivers (circa 2016–2019) to avoid signature issues.
• For embedded systems, configure the MT6261’s USB descriptor to auto‑load as a standard CDC ACM class (custom firmware only, not stock).
• Keep a dedicated Windows 7 or 10 VM for legacy flashing if Windows 11 proves unstable.