Disable / Turn Off Windows 7 Search Prompt / Warning Banner About Indexing
Solution 1:
Same annoying problem.
I found this and it works!
Go to: Control Panel > Folder Options > Search (tab)
And check: Don't use the index when searching in file folders for system files (searches might take longer)
http://www.sevenforums.com/general-discussion/76079-how-disable-click-turn-index-message.html