Too often, security programs significantly slow down the computer, causing lags in booting up the machine, launching programs and receiving email. Not only that, they can be incredibly annoying, popping up frequent messages or asking questions in techie lingo.

The main screen of the 2009 version of Norton Internet Security is streamlined and even includes a gauge to show much drain the security program is placing on the computer.

Now, Symantec (SYMC) has decided to radically rewrite its main security suite for Windows to directly address these problems. And in my tests, this new product, Norton Internet Security 2009, largely succeeded. It isn’t perfect, but it is the fastest, simplest and least obtrusive security suite I have ever used.

Being quick and quiet is great, but, of course, a security product also has to be effective against the vast number of viruses, spyware programs and other malicious attacks aimed at Windows. I don’t have a security lab in which to test such effectiveness. But PC Magazine does, and the magazine called the new Norton suite’s spyware and virus protection “extremely effective.” The magazine’s tests are described at http://www.pcmag.com/article2/0,2817,2330024,00.asp.

However, I wasn’t impressed with Norton’s optional antispam feature, which caused the only significant problem I ran into in my testing.

The new suite costs $70, and can be purchased at symantec.com and elsewhere. For that price, you get to install it on three PCs and you get a one-year subscription to its updates, which cost $60 thereafter.

Symantec is now including free support, even over the phone, though in my tests this support proved lousy. Norton Internet Security 2009 works only on Windows XP and Windows Vista.

I tested the new security suite on a Dell (DELL) desktop running Vista and on a Macintosh laptop running Windows XP as a “virtual machine,” meaning Windows and Windows programs ran simultaneously with the Mac operating system. Symantec assured me the program would run properly in this latter setup, and I had run the previous version of Norton successfully in the same environment.

The first thing you notice about NIS 2009 is the fast and simple installation. The process took under two minutes on each of my test machines.

File scanning is also much faster, partly because the new suite has a feature called Insight that allows it to skip the scanning and rescanning of many of your files. Insight gathers information about your installed programs and compares them against a list of programs Symantec knows are “trusted,” through either its own research or through scanning results voluntarily submitted by other users. These trusted programs are then exempted from future scans, saving a ton of time.

The new Norton suite has a feature called Insight which calculates how many of your programs it knows are trusted, and therefore needn’t be scanned repeatedly, saving time.

For instance, on my Dell running Vista, an immediate complete scan done before Insight analyzed the computer took more than an hour. But after Insight determined that over 70% of my programs were trusted, complete scans took 10 minutes or less. Of course, your data files, like Word documents and emails, still must be scanned, because they are typically unique.

To minimize the impact on users, the new Norton does scanning and other tasks only when it detects that the computer has been idle for at least 10 minutes. And new virus definitions trickle into your computer invisibly, in the background, rather than all at once in a major process.

Symantec is so certain that its product has a low impact on PC performance that it built a gauge into its new streamlined main screen that shows its drain on the main processor, or CPU.

NIS 2009 is also far less annoying than other suites I’ve used. In normal operation, it notifies you only when it has completed a background task or if there’s a threat or a repair that requires a user action, such as a reboot. And there’s an even quieter optional “silent mode” that can turn off nearly every nonurgent activity of Norton for up to six hours. Silent Mode is automatically activated during full-screen activities, such as playing games or watching movies.

The new suite has a bunch of other features, including a browser toolbar for Internet Explorer and Firefox that warns against fake and malicious Web pages, and that can securely enter your passwords and other information on Web sites. It also has an antispam feature for Microsoft (MSFT) Outlook and Outlook Express.

This antispam feature, which is off by default, was rated as weak by PC Magazine and, in my tests, it caused both Norton and Outlook Express to crash repeatedly in Windows XP running on my Mac. Symantec suspects this is a problem particular to running Windows the way I was on the Mac. After I reinstalled Norton and turned off the feature, all was well again.

But Symantec’s free tech-support service was not only unable to diagnose the problem, it didn’t even know the difference between Outlook and Outlook Express.

Despite this one glitch, I can recommend Norton Internet Security 2009 as a good way to protect your Windows computer with minimal impact on your time and attention.

Find all of Walt Mossberg’s columns and videos online, free, at the All Things Digital Web site, walt.allthingsd.com. Email him at mossberg@wsj.com.

But Sequoia Voting Systems is trying–really trying. Earlier this week thousands of phantom votes were cast in a Washington D.C. primary election that used Sequoia’s machines. This not a week after the Computer Security Group at the University of California at Santa Barbara demonstrated how astonishingly simple it is to hack the company’s e-voting systems.

Election officials initially blamed the cock-up on some defective memory in one of Sequoia’s machines. But the company denies this. “There’s absolutely nothing wrong with the [District's election] database,” spokesperson Michelle Shafer insisted. “There’s absolutely no problem with the machines in the polling places. No. No.”

OK. But if that’s the case, why were thousands of phantom votes recorded in the election? The answer to that question is particularly troubling: Sequoia doesn’t know. Neither does the D.C. Board of Elections. “All I can tell you is that we’re looking into it,” said Daniel Murphy, a spokesman for the D.C. Board of Elections and Ethics.

Well, that’s reassuring. Especially with the November elections nearly upon us …

But Sequoia Voting Systems is trying–really trying. Earlier this week thousands of phantom votes were cast in a Washington D.C. primary election that used Sequoia’s machines. This not a week after the Computer Security Group at the University of California at Santa Barbara demonstrated how astonishingly simple it is to hack the company’s e-voting systems.

Election officials initially blamed the cock-up on some defective memory in one of Sequoia’s machines. But the company denies this. “There’s absolutely nothing wrong with the [District's election] database,” spokesperson Michelle Shafer insisted. “There’s absolutely no problem with the machines in the polling places. No. No.”

OK. But if that’s the case, why were thousands of phantom votes recorded in the election? The answer to that question is particularly troubling: Sequoia doesn’t know. Neither does the D.C. Board of Elections. “All I can tell you is that we’re looking into it,” said Daniel Murphy, a spokesman for the D.C. Board of Elections and Ethics.

Well, that’s reassuring. Especially with the November elections nearly upon us …

Diebold Elections Systems is changing its name to Premier Election Solutions. The change to Premier signifies a new beginning for the company.”

– Diebold Press Release, Aug. 16, 2007

So the hundreds of votes that were dropped in Ohio’s March primary elections? The ones that Premier Election Solutions, formerly called Diebold Election Systems (DBD), insisted were caused by faulty antivirus software and not a critical source code error?

They were caused by a source code error–one that’s been present in the company’s software for the past decade. Said Premier (Diebold) President Dave Byrd, “We are indeed distressed that our previous analysis of this issue was in error.”

Yeah, I bet you are. But not nearly as distressed as the voters who will use the company’s machines in upcoming elections. Remember, Premier (Diebold) is the company that designed its widely criticized electronic voting systems in such a way that the the locks protecting them from tampering can be picked open with a hotel minibar key. The company posted a detailed photograph of its authorized key, showing size, shape, and cut pattern, on its online store. It’s the company whose e-voting machines once relied on hard-coded security passwords like “1,2,3,4,5,6,7,8″ and “11111.” It’s the company that evaded election transparency laws in North Carolina. It’s the company that can’t seem to safeguard its source code. And it’s the company that modified its machines without notifying election officials. Twice.

So much for that “new beginning.” Once a Diebold, always a Diebold, eh?