The nice thing about the folder context menu is that the search window will be already set to search only that folder.
Manual Registry Hack
Open up regedit.exe through the start menu search or run box, and then browse down to the following key:
Find the LegacyDisable key on the right-hand side and either delete it, or rename it to something else. That’s all you have to do… now you can right-click on a folder and see the Search… option again:
This will open up the search window for that folder, which will be a lot faster than searching the entire drive.
Of course you could just use the F3 key while you have a folder open, which will show you the same window, and is typically simpler. I primarily use the context menu for quick access to search a folders from the shortcuts I’ve added to the quick launch.
Downloadable Registry Hack
Simply download, extract, and double-click on ReEnableFolderSearchMenu.reg to enter the information into the registry. There’s also an included DisableFolderSearchMenu.reg file to put things back to the SP1 default.
Download ReEnableFolderSearchMenu Registry Hack