Microsoft has released a significant upgrade to its Windows Desktop Search program. It should now be considered a core component of Windows XP and should be installed on every computer. (Exactly the same technology is a core component of Windows Vista, inseparable from the rest of the operating system.) Here’s the page for downloading new version 3.0, which should also soon be available on the main Windows Desktop Search web page.

Windows Desktop Search indexes Outlook folders and My Document folders so that you can perform lightning-fast searches for a word, a name, a number, a scrap of text, anywhere it appears – documents, e-mail messages, contacts, appointments, or more. There’s a desktop toolbar that displays results as quickly as you can type them in, or a conventional window that easily permits narrowing in on search results.

For many people, this immediately becomes the single most important tool on their computers. If you are drowning in documents or unsorted e-mail messages, this gives you immediate access to information that would otherwise be lost.

Windows Desktop Search 3.0 is free and runs on Windows XP Service Pack 2. By default, it will index your mail folders – Outlook or Outlook Express – and your My Documents folders. If you have a previous version of Windows Desktop Search installed, version 3 will automatically upgrade prior versions 2.5 and above. (Users of earlier versions should manually uninstall them first.)

If you want to index folders on another computer (company files on a server, for example), or if your My Documents folders are redirected to a server, you have to install the Add-in for UNC/FAT. After restarting, you will be allowed to choose mapped network drives for indexing.

If you want to index the contents of PDF files, you have to install an add-in from Adobe, the Adobe PDF IFilter v.6.0.

If this is your first time installing Windows Desktop Search, leave your computer turned on with Outlook running overnight for it to compile the index. After the initial work is done, it will keep itself up to date in close to real time, with very little load on the system.