First of all, please forgive me, but my screenshots are in French due to my installation of Windows at work. It is still very easy to understand. I will include screenshots to make it more attractive.
Here is some background information:
- Windows 7 64bit
- Visual studio 2010
- The default display is 100%.
- AutoScaleMode: DPI
- AutoSize: True

My application is a window shape that was developed on a standard (small - 100%) display. Like this:

As you can see, the Small or Small display is the default choice.
Small display - 100% (default)
Here's what my app looks like with this option. This is the correct display.

- 125%
.

:
- / , , , Form_Load . .
- ,
- , .
, - . , , ... , Tab Control Listviews...
() (100%), , "", . ?