I'm starting to test a Winforms (using VS2008) app on Windows 7, and am seeing a strange problem.
It ran fine on the first couple of Win7 installations, but on the next two, many of my dialogs are too small, clipping the content by about 30%.
The app was developed on WinXP, and have not seen this problem on any of the XP installations!
Just starting to investigate the problem - don't have any details on differences between the systems that work and those that don't yet.
Edit
According to Kate's comment to one of the answers, Win7 will sometimes change to a custom text size when a new monitor is installed. The machine with the problem has a big, widescreen monitor, and when we checked (Control Panel + Display + Custom Text Size) - sure enough - the custom text size was set to 125%. Setting it to 100% made the problem go away.
I was then able to replicate the problem on WinXP by setting the text size to 125%.
So the question now becomes - how do you ensure a Winforms app is "custom text size independent"?
/Edit
As suggested, here are some screen shots. 1st one is from a Windows 7 computer, 2nd one is from my WinXP development system.
Although both screen DPI and Themes can change the size of controls, that is not the problem here because in your screen shots the window chrome and non-text control sizes are unchanged. The problem is you are not taking custom font sizes into account.
If you wanted to move controls around to fix them into a fixed form size you would have to perform calculations using the Control.AutoScaleDimensions property of your controls. That is a lot of work, don't do that.
Instead, lay out your controls using absolute coordinates and enlarge your form to contain the results. Set your forms' AutoScaleMode = AutoScaleMode.Font.
I had the same issue when a Win 7 user adjusted the default font size in "Control Panel\All Control Panel Items\Display"
When you have forms set to "Fixed Dialog" set the following properties on your form: .AutoScaleMode=Font .AutoSize=True .AutoSizeMode=GrowOnly so windows can resize your form based on the sizes of the child elements.
Display size, resolution, DPI, large fonts, small fonts are some possible causes.
来源：https://stackoverflow.com/questions/6983569/why-are-my-dialog-boxes-too-small-on-some-but-not-all-windows7-computers