
It was one of the main participants of the first browser war. Its distribution methods and Windows integration were involved in the United States v. It was superseded by Microsoft Internet Explorer 5 in March 1999. It is the default browser in Windows 95 OSR 2.5 and Windows 98 First Edition and can replace previous versions of Internet Explorer on Windows 3.1x, Windows NT 3.x, Windows 95 and Windows NT 4.0 in addition the Internet Explorer layout engine MSHTML (Trident) was introduced.

It attained just over 60% market share by March 1999 when IE5 was released. In August 2001 when Internet Explorer 6 was released, IE4.x had dropped to 7% market share and IE5 had increased to 80%. IE4 market share dropped under 1% by 2004. Internet Explorer 4 is no longer available for download from Microsoft.

However, archived versions of the software can be found on various websites.

This version also was included with Windows 98. Version 4.5 (only for Mac) dropped support for 68k Macs, but offered new features such as easier 128-bit encryption. The last non-Mac version was 4.0 Service Pack 2.

Internet Explorer version 4.0 for Macintosh Uninstalling IE4 became the subject of concern to some users and was a point of contention in later lawsuits (see Removal of Internet Explorer and United States v. Main article: Internet Explorer for Mac OS X On January 6, 1998, at the Macworld Expo in San Francisco, Microsoft announced the release of the final version of Internet Explorer version 4.0 for Macintosh.
