On a Windows XP machine, which of the following settings should be configured to allow dragging of files without holding the mouse button?

ScrollLock is a keyboard toggle key that historically locked scroll behavior in spreadsheets and has no relation to mouse drag functionality.

StickyKeys is an accessibility feature that allows modifier keys (Shift, Ctrl, Alt) to remain active after being pressed once, but it does not affect mouse button behavior.

MouseKeys enables the user to control the mouse pointer using the numeric keypad but does not enable drag-without-hold functionality.

ClickLock is configured in Mouse Properties under Ease of Access and allows the user to briefly press the mouse button to 'lock' it in a clicked state, enabling dragging and highlighting without holding the button. This is particularly useful for users with limited hand mobility and is the exact feature designed for the described behavior.