UltraSearch is an easy-to-use free search tool which can locate files and folders almost instantly.
The program achieves its high performance by directly accessing the NTFS Master File Table (MFT), which holds details on every file and folder on your PC. And so it's able to return results immediately, typically in around a second or two, without having to waste time or resources building an index: just enter a keyword and watch the results appear.
This only works with NTFS-based drives, of course. Use it on a FAT-based drive, or to search by content alone, and UltraSearch runs at more normal speeds.
While it's not a replacement for Windows Search, UltraSearch can be a useful addition, as the program makes it very quick and easy to search for files and folders by name.