Instant File Search Professional is a simple search engine for local files, enabling you to locate files by name, extension, size, creation or modification time.
There's no option here to search for the content of a file. And that means you can't use filters to, say, locate MP3 files by a particular artist, or JPEGS taken by a specific camera model.
Of course this also means the program doesn't need to run in the background, building up and maintaining an index. And you don't have to remember complex filter syntax, as you do with Windows Search. Instant File Search Professional is more like Windows Search used to be. Type a keyword; choose where you searching and (optionally) the file type (documents, images, videos and so on); select a file size or date/ time if you like, and click Go to start.
What happens next may be the real problem. As there is no index, the program must now search your entire drive to locate whatever you've specified, and despite being called "Instant" File Search Professional, this is inevitably going to take a while. If you value performance above all else then you'll be better off mastering the Windows search filters and using those instead.
Instant File Search is both convenient and easy to use, though, and if your system is fast, or you don't mind waiting a few seconds, then performance may not be an issue.
Instant File Search Professional offers easy, old-style searching where all the size, date and other filtering options are available up-front. The lack of an index means it's also relatively slow, but if you preferred the old XP-style searches then that may not be a problem.