If dreamed you that you cannot enter the computer because you do not know the code, warns you against acts about which commission you bitterly would regret further. If in a dream you try to pick up the code to someone else's safe or a door, then in real life you conceived a certain business which will involve from you not only costs of energy, but also big intellectual effort. The dream in which you forgot the code, means that you very accurate and pedantic person with whom it is pleasant to have commercial affairs.
Be sure and keep any other thoughts out of your mind before drifting to sleep as a cluttered mind can decrease the chances that you will remember your dreams upon waking. Also, focusing on remembering your dreams upon waking in the morning is another very important thing. This sounds very easy, but is often hard for some to do. Interpret a dream by "dictionary dream of interpretation"
When you very first wake up, simply think about your dreams. Don't allow your mind to drift off to other things, just lay there and think about the things you dreamt about the night before - dictionary dream meaning.