What language keyboard do you have?
If you have a UK English keyboard, it is the key at the far right of the centre row of letters a, s, d, f, g, h, j, k, l, ;, ‘, # - next to the <Enter> Key. I think this is the same on an Italian keyboard,
A US English keyboard - Shift+3
Some international keyboards don’t have a # key and you should try Alt+3.
For support from Sony’s websites, you need to find the correct model name for your Vaio - it will be something like SVP1321C5E - there will be a label somewhere. It may be hidden under the battery.
