Microsoft plans to distribute its forthcoming Internet Explorer 7 browser as a "high priority" upgrade through its automatic Windows Update service, group programme manager Tony Chor said in a posting on the IE Blog. 

The application will automatically download as a background process or when users run the auto update service to download and install security updates.

Users will be prompted when the application is ready to install. They will then be presented with a screen that advertises the improvement in the application, at which point it will be possible to choose to proceed with the new browser installation.

This method of distribution through the auto update service is considered aggressive and is likely to result in the majority of users proceeding to install the application.

But the approach could lead to compatibility issues. Internet Explorer 7 requires developers of some online applications to change their code to ensure that it works in the new browser.

Although the application has been available in beta since February, many online tools are expected to fail IE7 compatibility tests when the browser is released late this year.

Microsoft has released a Blocker Toolkit for enterprises that want to prevent the update from installing. But home users and small businesses are likely to end up with the updated version. 

"If my lowest browser support level was IE7, then it would be a dream," a web developer by the name of 'Steve' commented on the Microsoft blog.

"However seeing how many bugs and compatibility issues still exist with IE7, I see this as a nightmare for supporting various applications currently available, and websites (web apps) too."

IE7 partly replaces older versions of the browser, preventing the use of the old version for legacy applications in addition to the new IE7.

Microsoft justified its approach by pointing at the software's enhanced security levels.

The browser tightens restrictions on online applications in an attempt to curb browser-based attacks. It also warns users when they visit a known phishing website.

"These are just some of the security enhancements we've designed to help protect users from malicious software and fraudulent websites, and Microsoft recommends that all genuine Windows customers install IE7," wrote Chor.

The browser is currently in the Beta 3 stage and is scheduled for release by the end of this year.