.DEV File

The dev file extension is used for Windows Device Drivers. A device driver, or software driver is a computer program allowing higher-level computer programs to interact with a device.

Typically, dev files are stored in the Windows System folder and should not be opened or altered.

A driver typically communicates with the device through the computer bus or communications subsystem to which the hardware is connected. When a calling program invokes a routine in the driver, the driver issues commands to the device. Once the device sends data back to the driver, the driver may invoke routines in the original calling program. Drivers are hardware-dependent and operating-system-specific. They usually provide the interrupt handling required for any necessary asynchronous time-dependent hardware interface. 

Files with dev file extension are commonly found as drivers for Windows operating system.

How to open:

Drivers are used by the OS to handle various hardware, they are not for users to open or edit.

How to convert:

These files are generally not mean to be converted to anything else.