Okey, actually format C did fix the problem.

Hi there

As I mentioned in the title - Opera doesn't want to save my passwords. Of course, I checked the Settings, and I have this option turned on. For example: Yesterday I used facebook and Opera asked me if I want my password to be saved. I accepted it, but when I turn Opera off and launch it agains - it doesn't remember my password. I have to accept cookie politics again etc. I tried to reinstall Opera, the problem remained. I hope you will help.

PS. I had the same problem with Chrome, that's why I started using Opera :p