Question to the user interface designers.

Our company is young, we do not yet have a specialist designer on user interfaces ... Therefore, I decided to turn to the Habrasoobschestvu for advice / reference / suggestion.

TASK
Decision:
Subtask 1 Solution (Step 1 -> Step 2 -> ... -> Step m1)
->
Subtask 2 Solution (Step 1 -> Step 2 -> ... -> Step m2)
->
...
->
Subtask n Solution (Step 1 -> Step 2 -> ... -> Step mn)

So, to solve the problem, the user needs to solve n subtasks. In order to solve a subtask, you must complete a certain number of steps.
Passing a step involves entering some data by the user (for example, filling out a questionnaire).
During the passage of the step, the user sees all the previous solved subtasks and all the steps completed. He can return at any time to any step in any subtask. At the same time, the solved subtasks should somehow stand out and not take up too much space (well, you understand :).
In general, this is all very reminiscent of the "master of something" from windows. But only reminds. How is all this better visualized ??? Maybe someone saw examples of something similar or have ideas how best to do?

PS The interface will be developed on Windows Forms .NET. I promise to show the result and give the resulting code to everyone who responded :)
')
Pps
An example is
Task: user registration in the organization.
Subtask 1: User Information (Step 1 - Enter your name, year of birth, etc., Step 2 - Enter the data required for registering with the organization)
Subtask 2: Checking the entered information.
(Step 1. Verification of information on instances (reduced to pressing the button is completed)
Step 2. Entering information in other departments. )
Subtask 3: Issue of registration certificate
(Step 1. Order the form.
Step 2. Printing on the form.
Step 3. Obtaining a certificate by the customer.)