Type backtick on windows italian keyboard

Maybe, this is the best solution:

ITA-Dev Keyboard - Italian keyboard for developers

Install this keyboard, then remove any keyboard in Control Panel except this new keyboard.
Now you can type these chars:

` (AltGr + ')
~ (AltGr + ì)
À (AltGr + shift + a)
È (AltGr + shift + e)
Ì (AltGr + shift + i)
Ò (AltGr + shift + o)
Ù (AltGr + shift + u)
® (AltGr + r) registered
© (AltGr + c) copyright

Tilde is Alt+ 126 for normal one (~), Alt+ 152` for small one (˜)

You can find other codes here link