关于AUTO CAD2006安装的问题

我在我的电脑上安装AUTO CAD2006时出现下面现象，该如何解决？请高手教一下。先谢了！其中AutoCAD 2006 Setup.log里面的内容为
[12/5/2007 13:30:44] === Installation started on ADMINISTRATOR by Administrator ===
[12/5/2007 13:30:45] [Info] Windows Installer upgrade is not required
[12/5/2007 13:30:45] System Version = 3.1.4000.4039
[12/5/2007 13:30:45] Installation skipped: MSI Runtime 3.0
[12/5/2007 13:30:45] Installation started: .NET Framework Runtime 1.1
[12/5/2007 13:30:45] Command = "supportdotnetfxdotnetfx.exe" /q /c:"install /l /qb"
[12/5/2007 13:30:47] [Error: 1603] 安装时发生严重错误
[12/5/2007 13:30:47] Installation failed: .NET Framework Runtime 1.1
[12/5/2007 13:30:47] Installation aborted
[12/5/2007 13:31:00] === Installation ended ===