To start with, we made a choice to use Windows Search as our index & query engine when we began work on IE8 almost two years ago. We could have written our own engine, or we could have used a different engine, but it came down to a simple realization: we have a team of people here at Microsoft who are dedicated to creating a great search & indexing experience, and it’s called the Windows Search team (formerly known as “Windows Desktop Search.” And to avoid any confusion, we’re talking about the local search index team, not the folks who run live.com – those are separate organizations). The people on that team are experts at what they do, and by leveraging their technology, we get the benefit of all of their hard work and expertise. We consider the folks on the Windows Search part of the extended IE team (the same way you can consider, say, the folks on the networking team, who write TCP/IP for Windows, as part of the IE family).

Once we made the decision to use Windows Search, the next question was simple: what happens to IE8 when Windows Search is not installed? Well, on one hand, you could argue that IE8 should work just as well with as without Windows Search, but then we’d just be duplicating Windows Search inside IE, which reverses the decision we just decided not to make. So, while it was clear we would have to make some trade-offs in IE8 when Windows Search was not present, we still wanted to make sure that IE8 without Windows Search was superior to IE7.