Is Internet Explorer 8 displaying pages in exactly the same way on Windows XP and Windows 7 ?
Something I should know about differences in displaying web pages on IE 8/9 on different OS?
Since there are parts of the display that the browser gets from the operating system, there will be things that are displayed differently between Windows XP and Windows 7, even though the browser used is identical. The two examples that come to mind are form controls and fonts.
About IE9
IE9 will have complete or nearly complete support for all CSS 3 selectors, border-radius CSS 3 property, faster JavaScript, and embedded ICC v2 or v4 color profiles support via Windows Color System. IE9 will feature hardware-accelerated graphics rendering using Direct2D, hardware accelerated text rendering using DirectWrite, hardware accelerated video rendering using Media Foundation, imaging support provided by Windows Imaging Component, and high fidelity printing powered by the XPS print pipeline.
IE9 also supports the HTML5 video and audio tags and the Web Open Font Format
Resource from Wikipedia