Some web pages have larger margin

[Windows 7 Application Compatibility episode 2] 

I met customers saying that their pop up window got wider and taller after installing IE7 or IE8.

Yes, as for getting taller (larger in height), IE7's window height accounts for the content area only, not including the frame.

This can cause the window size changes. 

And IE7 also introduced minimum window sizes contraints.

If you encounter these kinds of problems, please check if these documents are helpful.

dialogHeight Property

https://msdn.microsoft.com/en-us/library/ms533724(VS.85).aspx 

In Windows Internet Explorer 7, the dialogHeight property returns the height of the content area and no longer includes the height of the frame.

dialogWidth Property

https://msdn.microsoft.com/en-us/library/ms533727(VS.85).aspx

In Windows Internet Explorer 7, the dialogWidth property returns the width of the content area and no longer includes the width of the frame.

 

open Method

 https://msdn.microsoft.com/en-us/library/ms536651(VS.85).aspx

height = number

Internet Explorer 7. Sets the height of the window in pixels. The minimum value is 150, and specifies the minimum height of the browser content area.

Prior to Internet Explorer 7 the minimum height value is 100.

width = number

Internet Explorer 7. Sets the width of the window in pixels. The minimum value is 250, and specifies the minimum width of the browsers content area.

Prior to Internet Explorer 7 the minimum height value is 100.