Sony PCG-NV290 - Manual (Page 138)

VAIO Computer Quick Start
138
❑ You can also press Fn+F4 to increase the volume. If you double-click the
Volume icon
on the Windows® taskbar, you can view your changes on
the Volume Control window.
✍
The Volume icon and Fn+F4 and Fn+F3 key combinations will work only when the
volume dial control is set to an audible level.