Google has released a new version of its desktop search tool, adding a preview feature to help find information more quickly and making some improvements to the interface design.

The update, Google Desktop Version 5, also has some new security features to fight phishing and other online attacks. Its release comes after security researchers reported some security holes in the search tool last month.

Google Desktop is a free tool that indexes the content on a PC, including e-mail, text documents and Web pages visited, and makes it available for searching. It also includes "gadgets," or small applications that sit on the desktop and display news headlines, a calendar, a to-do list and other information.

Microsoft and Yahoo offer competing tools, here and here.

A search in Google Desktop produces a list of results, including the file name and a snippet of the text. Several results can sometimes look similar, so Google has added a preview tool in version 5 that can show the contents of a file without having to launch the application it was created with, it said.

The update also aims to fight phishing and malicious code hidden in Web sites. If a user clicks on a Web link in an email or other document, the new Google Desktop will alert the user if it thinks the Web site is going to try to steal information or download malicious code.

Version 5 also updates the sidebar, a vertical control panel on the left of the screen. It can now "sample" the color of wallpaper on a PC and change its color to blend in, Google said. It also updates the appearance of the gadgets to make them easier to sort through and view.

The new version, which is still in beta like a lot of other Google software, was announced Tuesday in the Google Desktop Blog.

Google Desktop has come under fire from security researchers in recent weeks. In February, researchers at Watchfire said they'd found a flaw that could allow attackers to read files or run unauthorized software on systems running Google Desktop. Google patched the flaw, but the researchers said the software could be vulnerable to similar threats in the future. They reported a second flaw later in the month, and Google began investigating it.

Google is also trying to enter the broader desktop productivity market. Last month it launched a suite of Web-based software called Google Apps Premier Edition, which analysts say could become a competitor to Microsoft Office.