x-select-text

x-select-text is an alias for `gui-select-text' in `select.el'.

(x-select-text TEXT)

This function is obsolete since 25.1;
use `gui-select-text' instead.

Select TEXT, a string, according to the window system.
if `select-enable-clipboard' is non-nil, copy TEXT to the system's clipboard.
If `select-enable-primary' is non-nil, put TEXT in the primary selection.

MS-Windows does not have a "primary" selection.