Installing USBASP drivers on Windows 8 or 10 is bit tricky. As these versions of Windows require DEVICE DRIVER VERIFICATION , they do not allow unsigned drivers like libusb.

For programming 8051 or AVR you need this driver.

You can install by following methods :

1. Disabling Windows driver enforcement on boot up. Follow this link

This method requires SHIFT+ RESTART of Windows to enter advanced troubleshooting where we disable signature verification .After this you can install the libusb driver.

But in some laptops , this method fails on next Windows update.


2. Install libusb drivers using ZADIG application.

Zadig is meant to install a libusb compatible driver, for a device that does not yet have such a driver installed.

With the application running, you should see your USB device appear in the dropdown list

(click on the dropdown to see all devices).
You can also plug your USB device after Zadig is running, as the list is refreshed automatically. Its recommended to leave only the device you want to install a driver for, and unplug any other USB device.


You can also select the driver you want to install,( between WinUSB/ libusb-win32/libusb0 / libusbK )

Once you are satisfied with the selection and device description, simply click the Install Driver Button.

Caution :

If you select the wrong device,  Zadig will  replace its driver.

The responsibility is entirely yours try to pay attention to the device you select .Don’t just  press the install button on the first device you see,

If wrong driver is replaced , then some of your USB devices like wireless mouse may not work.


3. Best & Easy method

The USBASP windows driver was previously based on  libusb-win32. The certificate on the base drivers have expired and the library has now been superseded by libusbK.


Following is the procedure to install protostack USBASP driver.

At first when you connect the USBASP hardware to PC & open the Device Manager you see an exclamation mark against USBASP indicating that drivers not installed.


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If you open the PROGISP application ( to load HEX file on to8051) ,you see the PRG ISP icon greyed out ,as the programmer is not yet detected.

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Download the new USBASP driver from

This driver should work with version of Windows XP right through to 8.1 and the version 10 . (both 32 and 64 bit editions).

Because the driver is signed, there should be no need to disable driver certificate enforcement or use Zadig.

Unzip the downloaded folder.

Click on Install Driver application

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Once the driver is installed , under Device Manager you can see USABASP under

libusbK Usb devices

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Now ,open the PROGISP application to see the device ready.

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