To whom are you writing?
Your target audience matters!
First rule: it is you, who is guiding the reader! A CV is an open type of document, nothing is compulsory to include! A professional resumé is not a sheet of just actual facts. It is a marketing brochure where your work is for sale! Therefore, you should think about the so-called “target customer”. Think about it! If you are selling a washing machine, you would include in its brochure that it is silent, energy effective and looks good. You would not include that it weighs so and so much. The weight of the washing machine is irrelevant most of the cases – except, if you need to carry it around for some specific reason! There are always “excepts”! From this comes rule number 2: you will have several versions of your CV. So start tracking the versions!
If you are sending your CV speculatively to a recruitment company (or, for example, to a friend who has head-hunter contacts), include everything that you have an understanding of, as this way many different kinds of opportunities will probably await (at least with us). The more information you give about yourself, the greater the chance you have of finding suitable work. Even in this case, you should leave out the stuff that your are not interested in doing any more at any circumstances.
If you are applying directly for a specific position, then only include the knowledge which is relevant to the particular company. By all means include the company and the job in the application; never submit a CV without showing that you know what the company or institution does. They are likely to ask at the interview what you know about them. Being well-informed is an advantage, nay, a must.
If you are applying for a developer position you don’t need to emphasise that you are also adept at working with Windows Office. This should be evident. “Word-processing” simply doesn’t carry as much weight as, for example, “database development”. In addition, it doesn’t say much about your developer capabilities. The same can also be said for your graphical-software knowledge. It’s different if you are applying for a UI position, but in this case an over-emphasis on C++ is the anomaly – it doesn’t appear believable that you are as good a graphics designer as you are a software developer. If you still feel that you have taken to hear heart every technology you have come across, still take care that to portray a clear career path. We could say that “it should be possible to tag you”. Of course, generalists can be in trouble. If you are someone who does a bit of everything, then at least try and provide something on an industry basis to the reader about who you are.
A clear logic should be seen according to which you are building your career. Job hoppers are never welcome, though some “hops” can be explained.
Should you be sending your CV to a careers advisor however, then include everything, since this version will be temporary.