Remember how satisfying it feels to fit into place the final piece of a jigsaw puzzle? All the hard work is already done, and you finally get to see the results.

Well, businesses around the world, having spent a decade investing heavily in personal computers, networking and training so that they can share information easily, are about to fit a piece into the puzzle that will complete the picture-with excellent results.

The missing piece has a name: "intranet." It's the latest computer buzz word, and for good reason.

An intranet is an internal corporate or organizational network that uses Internet technologies to let employees browse and share electronic information remarkably easily. An intranet is a private version of the Internet's World Wide Web, but it's available only to people inside the organization.

On a Web page, various words, buttons or pictures serve as links to other pages. For example, if the word "Paris" is underlined in the text of a web page, clicking on it will take you to information about the French capital. It's a simple, even enjoyable way to sift through information.

Eventually the biggest impact of the Web will be how companies use it to stay in close contact with their customers. And it will be an increasingly important way for corporations to stay in touch with investors. Apple, Intel, J.P. Morgan, Microsoft and other companies already publish their annual reports on their Web sites.

But over the next 12 or 18 months the real pay-back to the typical business will come from using intranet web sites to give employees the information they need to be more effective.

Finding electronic information inside a company or organization today can be a real puzzle. Ironically, it's often harder to navigate your own network than it is to use the Internet to locate information about an outside organization.

Typically, to use a conventional corporate network, you first must know the name of the file that contains the information. (Until recently, these names were restricted to eight characters in length, which kept them fairly non-descriptive.) You also must know the name of the file's folder or directory, disk, and server. For a computer expert, finding files and sharing them across a network becomes second nature.

But the task can be a pain, even for an expert, when somebody else changes the name or location of a file, or changes its content. And for the non-expert, finding "lost" information can be particularly aggravating or even impossible.

What you really want is a page of text that describes what's going on so that, as you browse from one location to another, you have a guide to the content and location of files. This descriptive text, explaining how information is organized, is exactly what an intranet provides. Once you see a description of something you want to view, you just click on it to follow the link.

I became a believer through experience. We have published thousands of pages of internal information on Microsoft's corporate intranet. Here is an example of how well it works for us.

A marketer interested in sales figures clicks a link on her computer desktop, which brings to the screen a page that reminds her of various ways to analyze sales. The page tells her how up-to-date the data is and reminds her of restrictions on passing the information around. Getting the actual information is just one more click away.

I was amazed to discover that certain sales-analysis data is being accessed five times more often now that it can be reached through our intranet. This is a remarkable change, considering that the files weren't all that hard to reach before and that the employees using them are sophisticated about computers and strongly motivated to study the data.

From a manager's point of view, perhaps the best aspect of an intranet is that it doesn't take much effort or investment to get one going. Businesses that have networked computers already have everything they need. The only expense is to have an employee write the descriptive pages and links.

Most word-processing programs and many other productivity software applications already offer the ability to create Web pages with links. Special software to help create and manage large numbers of linked pages is available from many sources. To read the pages, employees can use applications they already know, or one of the free "browser" software packages.

Personal computing is rapidly evolving toward a web-based metaphor, in which any folder (directory) can be viewed as a Web page. When you look at the contents of a folder, instead of seeing just filenames or icons, you'll also see descriptive text.

The descriptions may prove so helpful that in the near future when a folder doesn't have any text, you may find yourself complaining, "Hey, put some explanation in here. Help me know what this does and how it works."

When I'm asked whether a company should do more with computers, I'm not always sure since it depends on the specific situation. However, for every business with PCs there's now a clear opportunity.

So perhaps my most timely general advice is: Get an intranet going in your company. It's a great tool, and you've already paid for it.