An installable driver is a Windows DLL that a Windows application (or another Windows DLL) can open, enable, query, disable, and close. An application can perform these operations by calling the following functions:
| Function | Description |
| CloseDriver | Closes an installable driver. |
| DefDriverProc | Calls the default installable-driver procedure. |
| GetDriverInfo | Retrieves installable-driver data. |
| GetDriverModuleHandle | Retrieves an installable driver's module handle. |
| GetNextDriver | Enumerates installed drivers. |
| OpenDriver | Opens an installable driver. |
| SendDriverMessage | Sends a message to an installable driver. |