The computer maker, which originally said it wasn't interested in pre-installing the software, changed its plans on 17 August. The company now intends to bundle a Java Virtual Machine (JVM) with every Windows XP computer it sells. This means users will be able to run Java programs without having to install the software separately.
Roger Frizzell, a Compaq spokesman, said: "Based on feedback we've been receiving from customers, we've decided now to pre-install Java with Windows XP on both desktops and portables."
Microsoft last month said it aims to phase out support for Java in key desktop software products. Beginning with Windows XP and its upcoming Internet Explorer 6 (IE 6) Web browser, Microsoft will no longer include a built-in JVM. Users will instead have to download the program from Microsoft's Web site or from a third-party vendor.
A JVM runs independently of a computer's operating system and allows virtually any type of computer - from a PC to a mobile phone - to run applications written in Java. Java programs can be used to liven up Web pages with dynamic features like a stock ticker, or to build Web-based applications such as online video games.
Computer makers have been split on whether to compensate for Microsoft's decision by bundling a JVM with their PCs. Dell Computer was the first of the major vendors to agree to bundle Java with its Windows XP machines.
The turnaround comes as Microsoft and Java creator Sun Microsystems continue a long-time dispute over support for Java. The companies settled a four-year-old lawsuit in January in which Sun had accused Microsoft of trying to "pollute" the technology by using an incompatible version in its products. As part of the settlement, Microsoft agreed to pay Sun $20m (£13.84m) and was restricted to using an older version of Java in its software. The company denied any wrongdoing.
Despite the settlement the battle continues. Sun last week took out a full-page advertisement in major US newspapers, urging consumers to "demand that Microsoft include the Java platform in their XP operating system and that the PC vendors' include the Java platform on their systems." Sun argues that pulling Java from Windows is an attempt by its biggest foe to stifle success of the technology.
As the battle over Java on the desktop continues ahead of the expected 25 October launch of Windows XP, industry partners such as PC makers and internet service providers are caught in the middle. Industry analysts, however, are unsure whether Microsoft's decision to stop supporting Java will have much of an impact either on the industry or on consumers.
"For all practical purposes it's a non-issue most consumers probably aren't going to notice," said Mark Driver, an analyst with Gartner, commenting on Windows XP's omission of Java.
Consumers who buy PCs without Java support will be prompted to download a 5Mbyte JVM the first time they come upon a Web site running Java applications. Users upgrading from earlier Windows operating systems that already support Java won't be affected.