Most of the current search engines are based on the keyword search and it returns a large amount of irrelevant information in response to the user query. This is because of the keyword matching does not consider the semantics of the keyword term. Ontology has been increasingly used to efficiently capture the semantics of the information which overcomes the problems associated with traditional keyword search. The importance of ontology is identified in the area of building semantic information retrieval systems for the specific domain and gains greater significance over the tradition keyword search.Knowledge representation formalism such as description logic is used to obtain the knowledge of the domain of interest and is used for the development of intelligent information retrieval system.Protégé is the widely used tool for developing and editing ontology with GUI which enables the ontology developers to describe the conceptual terms and relationship between them by creating taxonomies. This paper describes the steps for creating operating system ontology and the various aspects like subclassof, superclassof relationships and an overview of search algorithm have been described.