Internet Explorer 6

Microsoft Internet Explorer 6 (IE6) is a graphical web browser developed by Microsoft for Windows operating systems. Released on August 24, 2001, it is the sixth, and by now discontinued, version of Internet Explorer and the successor to Internet Explorer 5. It was the default browser in Windows XP (later default was Internet Explorer 8) and Windows Server 2003 and can replace previous versions of Internet Explorer on Windows NT 4.0, Windows 98, Windows 2000 and Windows ME but unlike version 5, this version does not support Windows 95 or earlier versions. IE6 SP2+ and IE7 were only included in (IE6 SP2+) or available (IE7) for Windows XP SP2+.

Despite dominating market share (attaining a peak of 90% in mid-2004), this version of Internet Explorer has been widely criticized for its security issues and lack of support for modern web standards, making frequent appearances in "worst tech products of all time" lists, with PC World labeling it "the least secure software on the planet." In 2004, Mozilla finalized Firefox to rival IE6, and it became highly popular and acclaimed for its security, add-ons, speed and other modern features such as tabbed browsing. Microsoft planned to fix these issues in Internet Explorer 7 by June–August 2005, but it was delayed until an October 2006 release, over 5 years after IE6 debuted.

Because a substantial percentage of the web audience still used the outdated browser (especially in China), campaigns were established in the late 2000s to encourage users to upgrade to newer versions of Internet Explorer or switch to different browsers. Some websites dropped support for IE6 entirely, most notable of which was Google dropping support in some of its services in March 2010. According to Microsoft's modern.ie website, as of August 2015, 3.1% of users in China and less than 1% in other countries were using IE6.

Internet Explorer 6 was the last version to be called Microsoft Internet Explorer. The software was rebranded as Windows Internet Explorer starting in 2006 with the release of Internet Explorer 7.

Internet Explorer 6 is no longer supported, and is not available for download from Microsoft.

It is the last version of Internet Explorer to support Windows NT 4.0 SP6a, Windows 98, Windows 2000 and Windows ME, though it is only available as pre-installed in Windows XP RTM—SP1 and Windows Server 2003 RTM; as the following version, Internet Explorer 7, only supports Windows XP SP2 or later and Windows Server 2003 SP1 or later.