Recently I changed my password on my computer but for the past few days I keep entering the old one when trying to log in or unlock it. Is there a word or phrase in to describe this? Another example would be writing 2013 for the year out of habit even though you know it's 2014.
There's no special word just for doing that with passwords that I know of.
However, the term for when you just do something physical like that without thinking about it because you done it a jillion times before is "muscle memory". Another example is working a combination lock you've been using for a long time, but not being able to actually tell another person what the combination is (without grabbing hold of the lock and working it and reciting the numbers as you get to them).
The problem of course is if the thing you've trained your body to do changes (eg: your combination changes), then the muscle memory actually works against you. At least until you can retrain.
Where "muscle memory" is the cause, "force of habit" is the result:
behavior made involuntary or automatic by repeated practice
In the past, this was attributed to facilitation: the lowering of the threshold for reflex conduction along a particular neural pathway especially from repeated use of that pathway; the increasing of the ease or intensity of a response by repeated stimulation. The idea was that with repeated performance of a task (e.g. writing out the year), it became a mindless task - one that could be performed with minimal mental engagement. This was well demonstrated scientifically in short-order cooks who, without thinking, knew exactly when to turn over eggs or pancakes while multitasking. The same could be said of entering passwords.
Now it is understood more in terms of brain plasticity, that is, there are specific long-lasting changes (more postsynaptic receptors, more dendritic connections, etc.) that actually occur in one's brain when a repetitive task is undertaken over the long term. Like "muscle memory", there is mindless "brain memory". A technical (and non-password specific but accurate) term for this habit/learned behavior phenomenon would be neuroplastic response.
Tamar Szabo Gendler characterized quite nicely this kind of automated response that thinking organisms naturally follow in their everyday situations, and called this alief, which she defines as the simple association rules we attach to actions, in constrast with belief, which are thoughtful reasoning that we use from time to time (most specifically when facing a new situation or when relying on aliefs fails).
Gendler distinguishes between belief and what she calls alief. The distinction can be appreciated either through examples or through a more theoretically informed elucidation of the notion of alief. Gendler herself offers myriad examples; here is a particularly simple one:
Unless one is particularly reflective regarding such matters, when one sees a sign exclaiming ‘glasses: $9.99’, one tends to form the belief that the glasses cost $10 but the alief that they cost $9. When one excitedly hurries to buy the glasses, even though one is in need of none, in all likelihood it is one’s alief that guides one’s action.
Consider another example. Every day I bike to my office. Today, however, they are predicting rain. (This virtually never happens around here.) Hearing this, I realize that I should take the car. I eat my breakfast, brush my teeth, reply to a couple of emails, take my notes, and head out. Once out the door, I assertively head towards the bike shed in my yard, never for a moment stopping to think that the car is parked on the street. It is not plausible to say that I believe the car is in the shed, nor that I believe I should bike to campus. No: I believe I should take the car, and believe it is not in the shed. My belief mismatches my behaviour—which frustrates causal explanation of the latter in terms of the former. What causally explains my behaviour is that I alieve I should bike to campus. This alief has been formed through years of pleasant routine associating mornings, sheds, bikes, campus, etc. Arguably it causally explains my shed-bike-retrieval behaviour most mornings, even on days my alief and belief converge, but is appreciated to do so only thanks to the occasional belief-behaviour mismatch.
For more infos, see: "Moral Motivation, Moral Phenomenology, and the Alief/Belief Distinction.", Uriah Kriegel, Australasian Journal of Philosophy 90 (2012): 469-486.
I too have had the same issue. The best way to roll out new passwords, is to write it down for the first few days of the change, and then try to force yourself to remember it. This works for me, I also say the password out loud five times, this ensures a higher chance of remembering the password in future.
The term I used for this was "Complacent Subconscious" as this detailed how I felt about not remembering it. I was complacent, and also allowing my subconscious to control the old password that was stamped in my mind.
It gets even harder when you start adding ?@ symbols, so I use a story based system to construct my new password.
In the psychological research of human error, this is often called a "Capture Error" (a habit 'captures' the current stream of actions). Another example from Norman (1988) "The Psychology of Everyday Things":
"I was using a copying machine, and I was counting the pages. I found myself counting '1, 2, 3, 4, 5, 6, 7, 8, 9, 10, Jack, Queen, King.' I have been playing cards recently."