to zurrain

to enable load preset you must first enable overclocking in the settings of the qcpufreq after that the load preset menu is available in the taskbar

PS: but if youre familiar with loading presets in the xterm then you dont really need qcpufreq

Edit: if its the convinience of button clicking, i will suggest you to use queen beecon widget in your desktop to easily switch between kernel presets
you could use the following command in the qbw for example to load the default preset
/usr/sbin/kernel-config load default | sudo gainroot