On some Toshiba laptops the Function Keys Mode "Special function mode" is set by default instead of "Standard F1-F12 mode". This means, you have to press the FN key to use the standard F1-F12 function keys.
You can configure the Function Keys Mode by selecting the "Special function mode" or "Standard F1-F12 mode" by the help of the HWSetup Utility.
To run the HW Setup program, click Start -> All Programs -> TOSHIBA -> Tools & Utilities -> HWSETUP
The HW Setup windows contains a number of tabs. Click the tab "Keyboard" and set your preferred mode: