CAD2006安装问题求助

从论坛里下载了CAD2006,很感谢提供资料的人,但是安装一直不成功,提示如下:
[6/14/2006 15:04:49] === Installation started on GHIDRI-WYS0G5J5 by Administrator ===
[6/14/2006 15:04:51] Installation started: MSI Runtime 3.1
[6/14/2006 15:04:51] Command = "msi\WindowsInstaller-KB893803-x86.exe" /quiet /norestart
[6/14/2006 15:04:53] [Error: 1603] 安装时发生严重错误
[6/14/2006 15:04:53] Installation failed: MSI Runtime 3.1
[6/14/2006 15:04:53] Installation aborted
[6/14/2006 15:04:59] === Installation ended ===
怎么回事?请指教,不甚感激...