I downloaded some new Java component, and now I want to add them to netbeans, but I don't know how.
How can I do that?
What kind of component is it? Do you mean a JAR file?
If so, then
open the project you are working on.
Select the project.
Right click on it and select "Properties"
Select "Libraries"
Select "Add external jar"
Browse to the JAR file and add it.