1. A method for taking screenshots of a failed application, the method comprising: concurrently running, in a single operating system process, a plurality of test modules respective each in a separate web browser window on a display screen; receiving a signal to indicate a screenshot is requested upon detection by a first one of the test modules of the failed application in order to determine a cause of the failure; and capturing screenshots for each of a plurality of overlapping web browser windows corresponding to the first test module, using an iterative process of successively capturing each of the plurality of overlapping web browser windows one at a time, wherein the captured screenshots exclude elements that are unrelated to the first test module; wherein capturing comprises: determining if a first window for actively taking a screenshot associated with the first test module is visible; hiding a second window associated with the first test module if the first window is hidden by, as a result of being intersected by, the second window; calling a first function of the single operating system to obtain dimensions for the first window; passing in the obtained dimensions for using a screenshot feature; calling a second function of the single operating system to show the second window that was hidden; and repeating the calling and the passing for the second window.