Thousands of hours are wasted every year waiting for computers to boot up. A Windows machine can take a couple of minutes to get going and to shut down again. In extreme cases, the entire process can take as long as 30 minutes, according to people who've filed lawsuits claiming that their employers should pay for this boot-up and shut-down time.

Software called Presto could provide an alternative to waiting. Demonstrated this week at Demo, a tech conference held in Palm Desert, CA, it joins a handful of products that have emerged recently in an effort to get people working on their computers faster. These products, offered by companies including Intel, HP, and DeviceVM, generally allow a person to boot up in less than 30 seconds, and in some cases less than 10.

When a computer running Presto is first switched on, the user is given the option to load the Windows operating system or Presto. If she chooses Presto, then the system launches within a few seconds, providing a task bar and icons for several applications, including a Web browser, an instant-messaging application, and the Internet phone system Skype. If the user wants to switch to Windows, she needs to log out of Presto and start up the machine as usual.

Presto, which will be made available in beta on March 16 and as a product on April 13 for $19.95, is built by software company Xandros, located in New York, and it's based on a slimmed-down version of the open-source Linux operating system.

Presto differs from other instant-on products such as DeviceVM's Splashtop in that it doesn't need to be integrated into the computer's hardware: it can simply be downloaded and installed. This also means that PC owners can use Presto regardless of the hardware they have. Even old laptops and desktops can be turned into quick Internet-access points using the software. Xandros also offers an online application store through which people can download software for Presto, including games, media players, and other tools.

One of the main reasons why modern operating systems take so long to boot is that they are very bulky: a huge amount of code needs to be read when a computer is first turned on. Consisting of far fewer lines of code than Windows, Presto needs just a few hundred megabytes of memory, says Jordan Smith, product marketing manager at Xandros. Microsoft's Vista operating system, in contrast, recommends at least 15 gigabytes of free disk space to install.

Rahul Sood, chief technologist of HP's Voodoo brand, says that modern operating systems also spend time establishing connections between hardware and software to help the system run faster when it's being used. But there is hope that Microsoft's Windows 7 operating system will address this issue and "make a huge difference," he says.

As Presto is installed on a computer, explains Smith, it inspects the machine, identifying the DVD player and the network card for instance, to determine what type of hardware it has. "During installation, we figure out what you have and install only the software that you need," Smith says, instead of software drivers for lots of different devices.

Since many applications now run over the Web, Smith argues that systems like Presto can perform lots of tasks simply via the browser. "Ninety-five percent of what [users] do is check the Web," he says. If a person needs to read a document in an e-mail, Smith adds, he or she can download Open Office, a free, open-source alternative to Microsoft Word.

"You need the browser and you need a network connection," Smith says. "You don't need the resources for running a first-person shooter game."