For a long time, some Microsoft officials have privately griped that PC makers don't present Windows in its best light. They clutter desktops with icons that are often little more than ads for third-party products; include confusing utilities that duplicate functions already in Windows; require lengthy setup; and configure PCs in ways that slow them down.

One consequence, in the eyes of these Microsoft executives, is to confer an advantage on the company's main operating-system rival, Apple.

Now, Microsoft is doing something about the situation. In a program unknown to most computer users, the company has been using its small chain of retail stores and its online computer store to sell customized versions of popular PC models that have been streamlined for a cleaner look and better performance. It calls these machines 'Signature' PCs. They retain the maker's brand, but sport a special Signature desktop and configuration. And they cost about the same as the identical stock version of the machine sold elsewhere.

Microsoft also offers a program that, for $99, will turn users' Windows 7 PCs into Signature versions, if the owner brings the computer into one of its 16 stores, due to grow to 21 outlets in coming months. All Signature computers come with 90 days of free phone support, as well as help at the stores' 'Answer Desks,' which are like the Genius Bars at Apple stores.

I've been testing three Signature models and comparing them with the same machines as sold elsewhere without the Signature modifications. I found the Signature versions much cleaner and easier to navigate and faster in a variety of tests.

I'd recommend that prospective Windows PC buyers who live near a Microsoft store, which are mostly in the West, or are willing to shop at the company's online store, consider a Signature machine. Information on store locations, as well as a link to online PC shopping from Microsoft, is at microsoftstore.com. Information on Signature is at signature.microsoft.com.

Some important caveats are in order. The hardware makers presumably believe, and some consumers may well agree, that the extra software, utilities and settings, which Microsoft removes or buries, are beneficial. Some of these, like offers to join game or music services, may be viewed as welcome bonuses. Others, like customized networking utilities, or launchers for the PC makers' own media software, may be viewed as better matched to the hardware, or superior to Microsoft's approach, even though they duplicate Windows functions. Many can be turned off, or removed, by a user with sufficient skill and time.

Also, Microsoft loads Signature machines with its own add-on software, such as its free email, photo and video programs, its Zune music and video program, and a stripped-down 'Starter' version of Microsoft Office, that includes only Word and Excel, plus ads, and an offer to buy the full version.

However, the company says the stores will remove any of these a customer doesn't want and even help the customerinstall competing software, such as Google's Chrome browser, or Apple's iTunes for Windows.

At my request, Microsoft supplied me with before-and-after laptops from Hewlett-Packard, Sony and Samsung. Over the past few days, I've been comparing the stock and Signature versions, and testing how much time it takes to set them up, start them and restart them in daily use, resume them from sleep, and shut them down.

The Signature desktop, which is labeled 'Microsoft Signature,' features a picture of a sunset over a lake as its wallpaper. It contains no icons other than the recycling bin. The Taskbar contains only icons for Internet Explorer, the Explorer file browser, and Microsoft's free email, photo and moviemaking programs. The system tray, to the right of the Taskbar, contains only the bare minimum of items, such as the network and battery indicators.

Signature machines are also configured with battery, audio and touch-pad settings Microsoft considers optimal. The usual third-party security software -- which is typically provided for only 30 to 90 days, makes you go through some setup, and nags you to subscribe -- is replaced by Microsoft's own Security Essentials program, which is free, required no registration or subscription and updates itself automatically. By contrast, my test H-P Folio 13 had eight icons besides the recycling bin, including several that were come-ons for music and game services. It also featured several H-P utilities.

A Sony EH37FX included an app from Best Buy that launched every time the PC started (though you could turn this off). Both stock machines festooned the IE browser with two space-hogging toolbars, including one from Microsoft's own Bing search service; the Signature machine had none.

The Samsung Series 7 I tested came with 10 extra icons and a bunch of special utilities.

Signature isn't the same on every machine. In most cases, it strips out some of the added software and utilities, and retains others, but hides them in a folder buried in the Start Menu. In some cases, however, where a utility is deemed essential for a computer's particular hardware, it retains these.

Such decisions, and indeed all of the Signature settings, are controlled by a team of engineers housed in Microsoft's retail division.

In my speed tests, Signature beat all the stock machines on all my trials, but the margins weren't dramatic, usually from a few seconds to 25 seconds. On the H-P, the differences were especially minimal. Across all three machines, the biggest differences were the time it took to set the PC up out of the box and the time it took to shut down the PC.

One Microsoft official told me that Signature represents 'Microsoft's perspective on Windows,' rather than that of the hardware maker.

In my opinion, although it may generally benefit Microsoft at the expense of the hardware maker, it also makes for a better experience for the user.