Device-control functions retrieve information about a device and modify its initialization state. Following are the device-control functions:
| Function | Description |
| DeviceCapabilities | Retrieves capabilities of a printer driver. |
| DeviceMode | Sets the current printing modes for a device by prompting the user with a dialog box. |
| ExtDeviceMode | Retrieves or modifies device initialization information for a given printer driver or displays a driver-supplied dialog box for configuring the driver. |
| GetDeviceCaps | Retrieves device-specific information about a given display device. |
| ResetDC | Updates the specified device context, based on the information in a DEVMODE structure. |
The printer driver, rather than GDI, provides the DeviceCapabilities, DeviceMode, and ExtDeviceMode functions.