Usually, I neither want nor need auto-complete or search suggestions. I find them more annoying than useful.   But there are rare occasions when I think such features might be useful. So, instead of having to turn the features on and off I bookmarked Google on two web browsers and used "preferences" to turn the unwanted features off on the bookmark on Opera (my preferred browser) while leaving them on for the bookmark on IE. When I need search suggestions, I just launch IE and use the "full-featured" version stored there.