[Q] Can't restore to factory reset? topic

I have a 2 months old N9 that has these symptoms:

1) about 6-7 hours battery life on average.
2) laggy screen swipes, touches, & rotation
3) warm back cover under light usage

I want to reset to factory & see if it will solve some of these issue.
Go under settings> backup & reset and it just locks up and hangs.

I don't root nor do anything XDA-ish.
What can i do to get a factory reset?