The Microsoft® Windows® Installer is an application installation and configuration service. WindowsInstaller-KB893803-x86.exe is the redistributable package for installing or upgrading Windows Installer.
System requirements
Supported Operating Systems: Windows 2000 Service Pack 3, Windows 2000 Service Pack 4, Windows Server 2003, Windows XP, Windows XP Service Pack 1, Windows XP Service Pack 2
Windows Installer 3.1 Redistributable supports Windows 2000 with Service Pack 3 or later, Windows XP, Windows XP Service Pack 1, Windows XP Service Pack 2 and Windows Server 2003. Windows Server 2003 Service Pack 1 contains Windows Installer 3.1 and therefore can't be installed or upgraded by this redistributable.
DownLoad Link :
http://www.fileserve.com/file/Tm7MmpW/WindowsInstaller-KB893803-v2-x86.rar