Is it worth testing the same version of IE on different versions of Windows?

Question

I'm putting together some virtual machines to test different browsers and I'm wondering if there is any compelling reason to be able to test the same version of IE on different versions of Windows. (i.e. IE8 on XP and Vista) I'm mostly talking about testing CSS to make sure it "looks right" across browsers, but if there were major differences in JavaScript I would want to know that too.

Are different versions of IE "generally the same" on different versions of Windows? Thanks!

Answer 1

The time and cost of testing different versions of windows would be better spent in other places. This would be one of the last things I would look at when looking for rendering issues.

Answer 2

I agree with both people who have answered previously, despite the fact that they disagree with one another.

In general, IE will act very largely the same across all versions of windows. However, there can be (and are) some occassional subtle differences. Whether these are important are not is up to you.

For the great majority of websites, I wouldn't bother with it. But for very precise web applications where you're using something like complex javascript, or if you require layout to be correct to the pixel for some reason, then it could be worth it. I'm thinking of cases where people are generating os-type applications in JavaScript where the DOM is really being pushed around, and where exact layout and flawless event-handling is critical.