Input functions disable input from system devices, take control of system devices, or define special actions that Windows takes when an application receives input from a system device. The system devices are the mouse (or other pointing device), the keyboard, and the timer. Following are input functions:
| Function | Description |
| EnableWindow | Enables or disables mouse and keyboard input to a given window. |
| GetActiveWindow | Returns a handle of the active window. |
| GetCapture | Returns a handle of the window with the mouse capture. |
| GetCurrentTime | Retrieves the current Windows time. |
| GetDoubleClickTime | Retrieves the current double-click time for the mouse. |
| GetFocus | Retrieves the handle of the window that currently has the input focus. |
| GetTickCount | Returns the number of timer ticks recorded since the system was started. |
| IsWindowEnabled | Determines whether the specified window is enabled for mouse and keyboard input. |
| KillTimer | Removes the specified timer event. |
| ReleaseCapture | Releases mouse input and restores normal input processing. |
| SetActiveWindow | Makes a window the active window. |
| SetCapture | Causes mouse input to be sent to a specified window. |
| SetDoubleClickTime | Sets the double-click time for the mouse. |
| SetFocus | Assigns the input focus to a specified window. |
| SetSysModalWindow | Makes the specified window a system modal window. |
| SetTimer | Creates a system timer. |
| SwapMouseButton | Reverses the actions of the left and right mouse buttons. |
For detailed information about the input functions, see the Microsoft Windows Programmer's Reference, Volume 2.