The 'web browser' choice screen' was made available at the start of March, and is part of a proposal by the software developer to help settle the EU's antitrust investigation, which was sparked by a complaint filed by the Norwegian browser developer in December 2007.
The screen offers 12 different browsers - a mix of popular programs such as Firefox, Google Chrome and Opera, along with lesser-known browsers such as Sleipnir, Green Browser, Maxthon, Avant and Flock.
It is available to Windows PCs that use Internet Explorer as the default browser via the Windows Update system, which is used to distribute security patches.
"This confirms that when users are given a real choice on how they choose the most important piece of software on their computer, the browser, they will try out alternatives" said Håkon Wium Lie, CTO at Opera.
"A multitude of browsers will make the web more standardised and easier to browse".
Opera also said 46 percent of all UK downloads of the web browser had come directly from the browser choice screen.
Web users will continue to be offered the choice screen well into May for existing Windows computers and for five years on new installations.
See also: Opera Mini 5 hits Google Android phones