Sy has a Samsung Galaxy Note 2 that restarts a lot. Sometimes it even locks him out. Leo says that it's worth doing a factory reset to get rid of any corruption in the software. But more likely, it's hardware which is due to age.
Sy could also root it. He should check out XDA-Developers.com. He needs to search for the exact model phone as his, and he can learn how to root the phone. This will allow him to create a better recovery or ROM like Cyanogen Mod, which can give it new life.