Install Internet Explorer 8

Internet Explorer 8 can be installed on Microsoft Windows Vista Service Pack 1 (SP1), Windows Vista, Windows XP Service Pack 2 (SP2), Windows Server 2008 and Windows Server 2003 Service Pack 2 (SP2). Downloads are available from the following locations:

Internet Explorer 8 Beta 1 for Windows Vista and Windows Server 2008
Internet Explorer 8 Beta 1 for Windows Vista x64 Edition and Windows Server 2008 x64 Edition
Internet Explorer 8 Beta 1 for Windows XP SP2
Internet Explorer 8 Beta 1 for Windows Server 2003 SP2
Internet Explorer 8 Beta 1 for Windows Server 2003 SP2 x64 Edition and Windows XP SP2 Pro x64 Edition




direct link for more info
Internet Explorer 8 Readiness Toolkit