This CodeProject article will give you a pretty good idea:
Upgrading VB6 to VB.NET[
^].
However, please don't expect good results. As the concepts of .NET are very different and powerful compared to absolutely dreadful VB6, the rate of success will be moderate at best, and the quality of translation can hardly be acceptable. It would be wise to consider the result of automatic migration only as the initial step, in best case. You will need to learn .NET seriously and use this technology properly in new project. In many cases, automatic migration can only delay this goal, compared to the strategy of writing your new project using .NET from scratch, using your VB6 source only for reference. It actually highly depends on how bad is your legacy code.
—SA