Abstract: A method, system, and apparatus are provided for retrieving and executing one or more diagnostics modules together capable of testing a single hardware component within a computer system in direct response to a user request. A request is received to perform a diagnostics test on the component. In response to the request, one or more diagnostics modules necessary to test the component are identified. Once the modules have been identified, the modules are retrieved from a remote server computer and installed at the computer system upon which they are to be executed. The modules are then executed, thereby testing the single hardware component. The retrieved diagnostics modules may contain only program code necessary to test the identified component.