Before
In the Before GUI, below, users had trouble figuring out what they were supposed to do. The original GUI was misleading. Despite left-to-right step numbering and labelling, users had to complete tasks in a non-sequential order.

Plus, the output, or "score" was rendered at such a small size and in such a hidden location that the score was effectively lost to the user. In the end, few non expert users could figure it out, and those that did found the process very frustrating.

After
In the revised GUI, below, all tasks actually flow from section 1 to section 2 to section 3 and follow accurate and task based section titles.

Then once in section 3, users simply press a single button to run a range of stress tests, then see the performance score in a clear, prominent, central position on the GUI.