Google has taken a major step towards challenging the dominance of Microsoft by signing a deal with Dell.
The agreement means millions of Dell computers will leave the factories with Google software already installed on them.
The software includes several personal computer applications, a Google toolbar and a co-branded homepage.
This could pose a serious challenge to the hold Microsoft has enjoyed on 90% of the world's computers.
The Seattle software giant has enjoyed a significant advantage over rivals, with computers automatically defaulting to Microsoft products.
In practice, most people stay with the default programs and search technology that comes with their machine.
The deal with Dell gives Google a potent weapon in its fierce rivalry with Microsoft. In the past, the net search giant has mostly had to rely on people downloading its software.
As well as individual downloads, in January Google introduced a free service called Google Pack, bundling software from a range of companies in a single download.
Included are Google's desktop, instant messaging and Google Earth mapping programs as well as the Firefox browser, Adobe's PDF reader and Norton anti-virus software from Symantec.
Now, a range of Google programs will come as standard on Dell computers. These include its desktop search software and toolbar.
More significantly, the default search engine on Microsoft's Internet Explorer will be set to Google.
"It's a really big deal for both companies. It's very good for them and very good for us," said Google CEO Eric Schmidt.