Huawei firmware update backup

Hi guys

I've just updated my Huawei Ascend G300 to Android 4.0.3 (from 2. something), and the phone made a backup file about the contacts, messages... etc, but I can't restore it. They are like 'contact.db' or 'calendar.db', and if I want to open them, it says 'Unable to open'.

So if anyone has a solution for it, pls help. Thank you.

Vakke