Input messages are sent by Windows when an application receives input through the mouse, keyboard, scroll bars, or system timer. The following list briefly describes each input message:
| Message | Description | |
| WM_CHAR | Results when a WM_KEYUP and a WM_KEYDOWN message are translated. | |
| WM_CHARTOITEM | Sent by a list box with the LBS_WANTKEYBOARDINPUT style to its owner in response to a WM_CHAR message. | |
| WM_COMMAND | Sent when the user selects an item from a menu, when a control passes a message to its parent window, or when an accelerator key stroke is translated. | |
| WM_DEADCHAR | Results when a WM_KEYUP and a WM_KEYDOWN message are translated. | |
| WM_HSCROLL | Sent when the user clicks the horizontal scroll bar with the mouse. | |
| WM_KEYDOWN | Sent when a nonsystem key is pressed. | |
| WM_KEYUP | Sent when a nonsystem key is released. | |
| WM_LBUTTONDBLCLK | Sent when the user double-clicks the left mouse button. | |
| WM_LBUTTONDOWN | Sent when the user presses the left mouse button. | |
| WM_LBUTTONUP | Sent when the user releases the left mouse button. | |
| WM_MBUTTONDBLCLK | Sent when the user double-clicks the middle mouse button. | |
| WM_MBUTTONDOWN | Sent when the user presses the middle mouse button. | |
| WM_MBUTTONUP | Sent when the user releases the middle mouse button. | |
| WM_MOUSEACTIVATE | Sent when the cursor is in an inactive window and any mouse button is pressed. | |
| WM_MOUSEMOVE | Sent when the user moves the mouse. | |
| Message | Description | |
| WM_RBUTTONDBLCLK | Sent when the user double-clicks the right mouse button. | |
| WM_RBUTTONDOWN | Sent when the user presses the right mouse button. | |
| WM_RBUTTONUP | Sent when the user releases the right mouse button. | |
| WM_SETCURSOR | Sent when mouse input is not captured and the mouse causes cursor movement within a window. | |
| WM_TIMER | Sent when the time limit set for a given timer has elapsed. | |
| WM_VKEYTOITEM | Sent by a list box with the LBS_WANTKEYBOARDINPUT style to its owner in response to a WM_CHAR message. | |
| WM_VSCROLL | Sent when the user clicks the vertical scroll bar with the mouse. |