Question: I have a question about design winforms.

Should I use, or not, group boxes in my forms? Is it good to the user? Give me some advantages, or disadvantages?

Some people think thar it's not goog enough to use.

What do you think about it?

Answer: 
One reason is to group RadioButtons. 

For every element you add to your UI you should ask yourself a few questions:

* Why do I add the element?
* Why is it located in this position?
* Why is it this color?
* Why am I not using a standard control/color/font/...
* etc.

If you can find good answers for this questions, you can include it. But you should be able to explain why you used it.

So for a group box you might say:

* It saves space on my form because I can prevent a label from repeating.
* It gives a clear seperation of other controls
* Users know it is used to group controls
Most applications need some kind of control grouping because they'd look cluttered otherwise.

GroupBox is a good thing because the user is used to it. But likely the user will recognize other grouping mechanisms as well. I like the Krypton Toolkit with its HeaderGroup approach to grouping, because it allows to display more group-related information in the top and bottom header. But if you don't need that, a traditional group box should be fine. On a dialog box, that is. On main windows, it doesn't fit in my oppinion, in contrast to the mentioned HeaderGroup, which easily fits both scenarios.