Microsoft has upgraded its desktop search, adding, among other things, the ability to preview documents. The upgrade requires Windows XP or Windows 2000 SP4.

Users will also be able to select which parts of their hard drive should - and shouldn't - be indexed by the programe. Microsoft has also set up a website to host third-party extensions to its program. The new version also includes easier setup options.

The software giant also outlined future features it intends to add to the desktop search: Tabbed browsing and a version for the workplace.

One thing the toolbar doesn't do is index information that users of other Microsoft online services, such as the Hotmail, may have stored in Microsoft servers. That puts it behind rival Yahoo which has started to do just that with its competing desktop search product.

The Microsoft toolbar can however index and retrieve metadata from over 200 different types of files, as well as the full text of some file types. At this point, the only e-mail files it indexes are those in Outlook 2000 or later versions and Outlook Express 6.0 or later versions. It also requires Internet Explorer 5.01 or later.

The product works well, delivers solid search results and has a good user interface, said Gartner analyst Allen Weiner. Consumers, however, are bound to be feeling overwhelmed by all the desktop search options that have become available in the past year from Microsoft, Google, Yahoo, Ask Jeeves and Blinkx, he said.

Trying out a desktop search tool is more taxing than testing online services, because it requires a software download and installation and time to learn how to use it, as well as the indexing of the user's hard drive, Weiner said.

Moreover, not all desktop search tools can co-exist peacefully, so testing one could interfere with the operation of another one, Weiner said. "It's not a market consumers will fiddle around with. People will select one and live with it," he said.

The stakes are high for desktop search vendors, because users' desktop search preference will dictate their Web search preference as well, Weiner said.

In the meantime, desktop search vendors face another challenge: getting users to grasp their tools' value, something that will be easier in the future when hard drives house significantly more multi-media content than they do now. "When you have 3,000 digital songs from five music services and video content from four different TV services, then desktop search tools become compelling," Weiner said.

Another analyst took issue with the toolbar's lack of support for the Mozilla Foundation's increasingly popular Firefox browser.

Although Firefox's share of the overall browser market is still small - 6.8 percent according to WebSideStory - its use is wider among tech-savvy users, said Guy Creese, an analyst with Ballardvale Research. "It's a big mistake to ignore Firefox users. They are early adopters and thus keen on trying out new stuff, such as desktop search tools," he pointed out.

The Microsoft search toolbar can be found here.