Ummm, you should be able to press Shift + a to get a capital a, but if you're looking. Take a look at what processes are running (ctrl + alt + del, task manager).
Some of them should be toshiba processes, look each one up to find out which controls their hotkeys.
Or if you want, just end each one and test between to see which gets rid of the hotkey you don't like.
Its a frigging Laptop, not a Labtop!!!!