How to disable Windows Desktop Search explorer integration after installing Office 2007
If you were as shocked and disappointed as I was when you found, after installing Office 2007 and installing the Desktop Search 3.0 to enable "Outlook Instant Search," that the default Search behavior in Explorer had changed without asking you, you'll want to change this registry key.
In RegEdit, go to HKEY_CURRENT_USER\Software\Microsoft\Windows Desktop Search\DS and set "ShowStartSearchBand" to 0, and you'll get the default search behavior back.
And while you're at it and poking around in the registry, you might as well go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\ContentIndex and set FilterFilesWithUnknownExtensions to DWORD with the value of "1" in order to enable full-text searching of files (like code!) that Explorer by default skips over.
Don't you hate it when you KNOW that there's a file in that directory with the text "foo" - you can SEE the file - but the standard explorer search doesn't even bother to look in in the file? That's because it doesn't even bother to look in files that don't have their extension registered with a known IFilter. But you don't care, just flip that bit in the registry, and you'll get full-text search of REAL FILES (not "indexed three hours ago") from your trusty Explorer search bar.
Or, go download Chris Sells' .reg file over in my Power User Windows Registry Tweaks section. Either way, take back your Explorer!