I have installed Ubuntu 12.04 but key
Fn+F3 and etc doesn't work like in Windows 7.
I have laptop ASUS ZenBook UX32VD. How can I enable those keys?
The base install of Ubuntu 12.04 doesn't support, by default, the keyboard functions for your particular machine. You'll need to install drivers for it, basically. Help.ubuntu.com has an awesome wiki page detailing how you can go about doing that.
I highly recommend alternative 1 (from the wiki page):