While most insects do have wings, there are some groups that do not. Apterygota is a subclass of insects that is wingless and considered primitive.
Bristletails, diplurans, proturans, silverfish and springtails are all insects that do not have wings. Fleas are another kind of insect that lack wings. There are also insects that have been bred or modified that do not have wings or have nonfunctioning wings. There are flightless fruit flies, but they are an example of a species bred to have flight impairment. By contrast, the majority of insects do have wings and often more than one set of wings.