I recently tried to upgrade my system, It was said that I dont have enough RAM. So I rebooted my system and I have a padlock, empty & an arrow on my screen.. I have NO idea what it is and can't get passed it to restore my system back to it original state.... What do I do?
Take it to Apple and pay to place some more RAM into the machine.
Lets see, Apple quoted me $435 to upgrade to 8GB, so since you likely need 4GB I'd say they would likely charge about $380.
You could add more RAM yourself, there is a little door under there someplace, there is Crucial.com which will give you the right RAM for your machine, there are videos on YouTube, so I guess you could add more RAM yourself to save a lot of money.