http://connect.microsoft.com/VisualStudio/feedback/details/759413/winform-dialogs-displayed-differently-by-vshost-exe-and-exe-using-vs-2012-when-formborderstyle-set-in-form-codebehind

So you could try workarounds suggested there:

“Several workarounds are available.
1. In order to achieve runtime parity between NETFX 4.0 and 4.5 applications, manually change SubSystemVersion compiler option in the project file targeting NETFX 4.5, to a value lower that 6.00, see this article for details: http://msdn.microsoft.com/en-us/library/hh965708.aspx For example: add the following property to your project file: "<subsystemversion>5.01</subsystemversion> " Note that 64bits OS does not support all subsystem versions numbers.

2.In order to see the same layout when running the application from Visual Studio and as a standalone executable, for applications targeting FX below 4.5, disable vshost process when debugging: go to the project properties page, -> debug tab-> uncheck the "Enable the Visual Studio hosting process"

3. Set windows theme to "basic" on your development machine, then design time layout and layout during debugging with vshost enabled, will be the same as standalone runtime layout regardless of the target framework. If you are building a 4.5 application you would need to request the user to disable themes on the target machine or apply workaround #1.  “

So please try those workarounds and let me know for the results. If no one of those workarounds helps, please post simple sample that demonstrate this issue in order to be able to continue investigating this issue further.

Please let me know if you have any further questions.  

Hi Frank,

I'm looking and looking, but I don't see any difference between the left and right images. What am I supposed to be seeing here?