Hi mzab,
Welcome to Sony Community!
We're sorry to hear about this. When did it happen?
Here is some steps to follow:
1. Check the CAPSLOCK, NUMLOCK keys, ASSIST button if it works.
2. Uninstall and reinstall the keyboard driver from device manager .
3. Power Reset the unit
4. Reset BIOS to default
Please be aware that upgrading to Windows 10 has certain limitations on the functionality of the laptop.
For further assistance regarding your concern, please contact the Sony offices/Sony representative offices nearest to your place of residence in Asia Pacific region http://www.sony-asia.com/countryselector.html?hpid=countryselector:AsiaPacific. Due to proximity, they are in a better position to respond to your questions or concerns.
Regards,
Jen
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