Does Windows OS affect cross-browser compatibility?

[browsercheck]

This is probably a pretty basic question but I wasn't able to find a clear answer anywhere else - if I'm testing for cross-browser compatibility, is it enough to test IE 5, 6, and 7, Firefox 2, etc in just Windows XP, or do I also need to test each of them in Vista, Windows 2000, ME, and so on?

I read that IE 7 in Vista may have issues due to the protection-mode it automatically runs in (and the site might be fine in IE7 on XP) but I'm wondering if that's the only case.

[tedster]

Hello browsercheck, and welcome to the forums.

I used to test on different OS for many years - and the last OS related problem I found was quite a few years ago, and I've I stopped worrying about it or testing for it now.

The last (apparent) OS problem I found was about 6 years ago. It really came from different settings of System Fonts in the Windows Control Panel. it seems that some big brand laptops came preloaded with Win2K and shipped with System Fonts set to large. But the issue wasn't really the OS - it was the System Fonts setting.

There are two areas of testing that people seldom do, but they can be important for some designs - much more important than different OS:

1. Testing at different color depths, especially 16-bit and 24-bit (32-bit)
2. Testing with different sizes of System Font settings

Both those items are easier to test for than true OS issues.

[phranque]

you should also test very small and large display resolutions with the browser set to full screen.
1024x768 is a common 14-15 inch laptop display resolution and most 20+ inch displays are at 1600 to 1920 widths.
they can both break things if you aren't careful...

[browsercheck]

Thanks for the input! This is very useful - I had never considered the color depths or system font sizes as potentially causing an issue.

Also, I did test with resizing my browser window, but not with actually changing the resolution of my screen - good to know.

Thank you again!