Some comments to the VB Upgrade Guide and how to approach the Migration exercise.
Link to Getting started: Tips for VB6 to VB.NET 2.0 migration
An excerpt of the above page that I believe is important to always remember when approaching a migration:
Functional equivalence
A migration of any kind tends to face a quandary. "As long as this application is being moved over," someone will ask, "why don't we add some features?"
In organizations large and small development managers are constantly pressed to create new functionality, but the essential goal when you move an application is to create a baseline reference of the app and the development team. How long does it take to develop/migrate? What has to be done? Does it still work the same? These are questions you need to answer, but cannot answer with assurance, if your application has morphed into something new.
Said Pleas, "When you add a feature, you are satisfying somebody's need and that can be important if they have the budget." It can be difficult to focus on the objective of learning as you migrate, Pleas indicated, but that is just what is needed if you are to achieve a successful outcome.
"It is very important to separate the actual migration project from further advances, said Eugenio Pace, product manager, Patterns & Practices, Microsoft. "We have found separating the migration [from other functional development] is very pivotal."
"It is important because you now will have a baseline against which you can test. If you had a test [before in the VB6 version], the application should now perform in the very same way," he said.
Achieving a "functional equivalent" is crucial, said Fedrico Zoufaly. As Zoufaly, Pleas and their co-authors point out in their migration guide, the process that you use becomes a key factor in upgrade projects. Maintaining functional equivalence as you move into the new technology is highly recommended.
Put another way: Take something over that you know is working in COM or DCOM and then you can actually see what is needed to make it work in .NET.