LOOMFIELD, Conn. -- ON a May morning in Mary Kay Rendock's fifth-grade classroom here, the sounds of the dawning school day were echoing everywhere. Lockers banged outside in the hall, 10-year-olds chattered as they settled into their seats -- and a crescendo of chimes emanated from 15 laptop computers as every student in the room booted up.

At Carmen Arace Middle School, where laptops are something that students carry with them every day, Ms. Rendock's students knew the drill. Before the tardy bell, they were already scrolling through pages on their screens, lining up at the printer in the back of the classroom and handing over their assignments.

"Boys and girls," Ms. Rendock said as she leafed through the stapled papers, "these are impressive."

But in the midst of all the activity, one girl was barely stirring. She sat slumped in her chair, staring at the black screen of a computer that wouldn't boot up. Ms. Rendock walked over to try troubleshooting. Looking worried, she asked, "Do you think you lost anything when you shut it down?"

Such are the highs and lows of laptop schools, a growing cadre of educational institutions that have taken the controversial step of equipping every student with a portable computer to use at school and at home. For years, technologically inclined educators have been pushing this approach Ñ often called one-to-one computing Ñ as a radical way to provide Internet access and word-processing programs to students at any time, anywhere.

Issuing laptops may be expensive, but advocates (not to mention customer-hungry computer companies) say it is far better than shuffling students off to shared computer labs, where sessions sometimes last no longer than 40 minutes once a week. And it is the best way, they say, to bring the power of the Internet to all children, even those in the poorest families.

Yet many educators are still engaged in vigorous debates about whether laptop programs are really the panacea that some claim. In school districts with emaciated budgets, are laptops worth the pain of cutting other resources? What about the costs of technical support and teacher training? Won't the computers be magnets for muggers? And who is going to make sure that students use them for schoolwork as opposed to instant messaging and video games?

"Before they spend money on something like that, they ought to fix the leaky roofs," said Kenneth Reinshuttle, executive director of the Fairfax Education Association, a teacher's union in Virginia. The Fairfax schools were the focus of similar criticism five years ago when officials floated a proposal to require laptops for each student.

But given the advances in wireless networks and the news that some laptops now cost little more than $1,000 each, the push to outfit students with computers has taken on an inexorable logic of its own. NetSchools, a company that provides hardware, software and wireless networking, is supplying computers to 68 public and private schools, up from 10 when it started in 1997. More than 800 schools and 125,000 students are taking part in Microsoft (news/quote)'s Anytime Anywhere Learning program, which the company started with Toshiba (news/quote) in 1996.

Henrico County, a district near Richmond, Va., recently purchased a $19 million networking package that included 23,000 Apple iBooks, which are being distributed this month to every high school student. In Maine, Gov. Angus King persuaded lawmakers to use $30 million of the state's budget surplus to supply portable computers for every seventh and eighth grader in the state, starting next year. And last year in Community School District 6 in upper Manhattan, administrators expanded a laptop program to include 4,500 students.

"It's clearly taking hold," said Mary Cullinane, manager of the Microsoft program. "Now we just need to figure out a way to do it for everybody."

At Carmen Arace Middle School, a public school in a low-slung brick building serving grades five through eight, the laptop program was initiated in response to a concern far graver than leaky roofs. The school, administrators worried, was failing its students. Scores on standardized tests had plummeted at the school and absenteeism was running high.

To jump-start a turnaround, the superintendent at the time came up with a proposal in 1996 to give every student Ñ all 850 of them Ñ a laptop computer and to install wireless networks in every classroom. The school board found support among parents and unanimously approved the plan, signing up for a $2.1 million, five-year program with NetSchools. To pay for it, the board cut several student aide and secretarial positions and used money that had been earmarked for PC purchases.

After three years of having students tote their computers everywhere, many teachers said, the school has come to feel like an entirely new place.

Everywhere you turn, children walk the halls with their blue-and-gray laptops in hand, usually carrying them like briefcases by their plastic handles. (The handles are NetSchools' solution to the problem of overstuffed and heavy backpacks.) Many of the laptops are covered with stickers so worn it is impossible to make out their images. A boy in Ms. Rendock's class had set the wallpaper on his computer desktop to display the cartoon images of Dragon Ball Z, a video-game series and television show popular among some pre-teenagers.

On that morning in May, students in classrooms across the school were typing at their laptops, scrolling through Web pages about Anne Frank, using e-mail to turn in math assignments and poring over online maps to learn about the Revolutionary War. When the machines were not required for a lesson, teachers barked, "Lids down!" and the room resounded with the snaps of computers folding up.

Test scores are starting to show improvement as well. In October 1995, a little more than a year before the first laptops arrived, only 40 percent of eighth-grade students had met statewide reading goals. By 1999, the last year in which the test could be compared to the 1995 version, the percentage of eighth graders achieving those goals climbed to 60 percent.

Whether that upswing is directly attributable to the laptop program is, however, an open question, since new reading and math programs were instituted at the same time. But the computers are almost surely responsible, teachers say, for what many of them single out as the area of greatest improvement Ñ children's writing skills.

Teachers say that students are more likely to practice writing at home, and they no longer roll their eyes when asked to write second drafts, since doing so doesn't require completely rewriting their work.