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Looking for a great PC that runs a fully fledged version of Windows XP but weighs less than two pounds? Well, it's here — at least if you can live without the "great" part.

The Samsung Q1 is one of the first computers made to Microsoft Corp.'s Ultra-Mobile PC specification, which was formerly known as the company's Project Origami.

It's a tablet-style computer, about the size of a trade paperback and, at 1.7 pounds, only slightly heavier. It has a 7-inch screen with a few buttons around it, but no keyboard or mouse.

If the Q1 were red, you'd think "Etch A Sketch" when you saw it.

The main way of communicating with the UMPC is by touching the screen, either with your fingers or an included stylus. It's the first time Microsoft has made a push for touch screens outside of its cell-phone and personal-digital-assistant software.

The concept is similar to the Windows XP Tablet PC Edition, which launched in 2002, but Microsoft has encouraged tablet manufacturers to use screens that don't respond to touch, only to special battery-powered styluses.

Also, Tablet PCs are usually the size and shape of laptops, with built-in keyboards. The UMPC is a more stripped-down device, limited in its uses and easier to carry around.

The Q1 lists for $1,100. Some have complained about that price, but I think it's mostly a matter of disappointed expectations — Microsoft had said the UMPCs would cost between $500 and $1,000.

The other manufacturer in the first wave of UMPCs, TabletKiosk, is shipping a "limited" production run of its own device for $900, and is expecting more inventory in a month or so. Asus is also bringing out a UMPC.

The Q1 is still cheaper than Tablet PCs, which start at $1,500. Laptops that weigh 2 to 3 pounds usually cost $2,000. The OQO, an even smaller computer that weighs less than a pound, costs $2,100 in its tablet version, and its 5-inch screen is pretty squint-worthy.

The Q1 has a 900-megahertz Intel Celeron processor and a 40-gigabyte hard drive, all sufficient for its likely uses. It doesn't have an optical drive, so you may not be able to install all the software you need unless you get Samsung's optional drive.

So who needs a UMPC? Well, Samsung sees students and salespeople as the early adopters. I think they're wrong.

Students need something they can write and play games on, and the UMPC isn't it. You can write on it with the stylus, and the software does a great job of recognizing what you write, but it gets tiresome.

You can also call up an on-screen keyboard for thumb-typing while holding the device, but it really doesn't work well. It obscures too much of the screen and it doesn't work when you hold the screen vertically because the "keys" overlap. Thirdly, the power cable connects exactly where you need to hold your right hand for thumb-typing.

The Q1 has a joystick-type button and a four-way rocker button that could be used for games in the manner of Sony's PlayStation Portable, but it's hard to see ordinary PC games, designed for mouse and keyboard, working well with this control scheme.

Mobile business people will probably start by looking for something the Q1 doesn't have: a PC card slot. That's where the new mobile broadband cards go — the ones that give DSL-type speeds over cellular networks. The Q1 does have a CompactFlash slot and built-in Wi-Fi and Bluetooth.

All this doesn't mean the UMPC concept is dead in the water. It could be a nice gadget to have around in the house as a complement to the desktop computer, and for light use on trips.

I folded out the stand built into the back, and used it as a Web radio on the kitchen table. I listened to audio books, streamed from the desktop hard drive. I watched a movie on the couch, also streamed over Wi-Fi. I used the stylus to play Microsoft Sudoku while standing on the subway.

The Q1 would make a good e-book reader too, except for a bug. When I hit a button to change the screen orientation to vertical, the screen started sensing touches at the wrong places, making the computer nearly useless.

Samsung should be able to fix that bug soon, but there are several other annoyances, like the overlapping DialKeys in vertical mode and the location of the power jack, that indicate not enough time was spent on integrating software and hardware.

If you tap the Wi-Fi icon in the taskbar, you're prompted to "right-click for more information." You're supposed to be able to right-click by pressing with the stylus and holding, but it doesn't work in this case.

Many dialogue boxes are so large that they don't fit on the Q1's 800-pixel-by-480-pixel screen. You'll be hunting for the "OK" and "Cancel" buttons till you hit the hardware button that tells the screen to simulate the more standard 800-by-600 resolution.

Apart from niggling annoyances like that, a UMPC needs better battery life than the 3.5 hours quoted by Samsung. Using Wi-Fi to stream media around the house, I got less than two hours use on a charge. It's not ultraportable if you need to plug it in all the time. (Samsung does sell an external battery that extends life up to 9 hours.)

Still, the UMPC is not a bad concept. It's easy to carry around, and apart from the annoyances, the touch screen is an intuitive interface that's much nicer than the touch pads of regular laptops.

But integration and battery life need to improve before the UMPC is going to find its market. Microsoft has a track record as a tenacious improver, and its hardware partners will no doubt figure this one out.

Just give them a year or two.