There is this white stuff growing on my wood desk,?

While you can remove the symptom (white powder on the desk), the bigger issue is what is causing the desk to react that way?

I recommend buying a temperature and humidity gauge to learn what the humidity level is in the room where the desk is. Optimal is 30-50% humidity. Higher than that and you experience health and allergy problems, in addition to conditions like on your desk.

There may also be an air leak issue around the window itself. Excess moisture is what creates mold conditions. So while you can continually wipe off the mold on the desk, I am more concerned with the larger issue causing it to happen because it is affecting your health as well as the desk.

have pictures instead of posters, or frame the posters. don't have them as your favourite band make it something like a skyline or an arty poster. Also you don't want massive in your face colours so hot pink is a big no no. go for something softer and more sofisticated. it can still be pink but a more grown up pink. as you mentioned a theme is a good idea, for instance do you have any colours that you can't change but only a small part of the room/is that colour. if so then paint the door frames and the skirting board that colour. A good idea for insiration is to look on youtube to see what teenage volgers have

I have this exprerience too. I think it is "mold". It can be easily wipe off by a wet cloth. To keep it free of this, spray and wipe with some protectant cream like Amorall or Johnson Kit UV Guard. This gives a shiny appearance and dust-free surface.

Use a little bleach water and wipe off.. If it was moved from an area w/less humidity that is moisture