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
GroupBox are common pieces of UI found in most Windows application and thus they are commonly recognized by users. I think they're very useful to communicate a user that some controls are related in some way (for example RadioBox or CheckBox), plus since contained elements are seen as it's children you can menage them more easily.