The tree is indeed one possible solution.
One alternative solution is to use a three-column table: the first column can display a proper image (e.g. checkmark for steps already completed, an arrow for step under execution or nothing for steps still not executed); the second column a description of the steps and the results may be shown in the third column (and maybe some columns more if needed).
The table permits you several aestetic customizations like for example painting in green the background of cells for steps with good result and in red those for defective steps, writing in bold the step under execution... Attached is a sample panel.
In my opinion in case of a simple sequence of tests without hierarchical connections between them the table is a more powerful tool for your needs. On the other hand, if your test procedure is adaptive so that some tests are executed or not depending on the results of preceding tests you may find the tree more suitable to give the user a visual feedback of what's going on.
