AutoCad Mechanical 2012 installation fails @ .NET Framework Runtime 4.0

[jamengr]

 .NET Framework Runtime 4.0 is already installed

yet the AutoCad installer attempts to reinstall it, fails & quits.

2012/4/20:16:13:57    Jim R&D    JIM_M    === Setup started on JIM_M by Jim R&D ===
2012/4/20:16:13:57    Jim R&D    JIM_M    Launch
2012/4/20:16:14:11    Jim R&D    JIM_M    PageOpen    LaunchDialog        
2012/4/20:16:14:42    Jim R&D    JIM_M    PageOpen    LicenseDialog        
2012/4/20:16:14:48    Jim R&D    JIM_M    PageOpen    ProductInfoDialog        
2012/4/20:16:14:56    Jim R&D    JIM_M    PageOpen    ProductSelectionDialog2        
2012/4/20:16:16:53    Jim R&D    JIM_M    PageOpen    FullProgressDialog        
2012/4/20:16:16:53    Jim R&D    JIM_M    Installing .NET Framework Runtime 4.0: C:\Autodesk\AutoCAD_Mechanical_2012_English_Win_64bit\3rdParty\NET\4\wcu\dotNetFramework\dotNetFx40_Full_x86_x64.exe /q
2012/4/20:16:17:10    Jim R&D    JIM_M    Install    .NET Framework Runtime 4.0    Failed    Installation aborted, Result=1603

[TravisNave]

Your product is failing to install because the prerequiste program required by the installer is newer than the version being installed. Please uninstall the prerequisite program causing the issue and run your installer again.

For more information about this process, please see my KB link here:

http://forums.autodesk.com/t5/Installation-Licensing/Some-Products-Fail-to-Install-Result-1603/td-p/...


.NET Framework issues can be resolved using the .NET Framework Cleanup Tool. More information about this tool can be found at my discussion thread here:

http://forums.autodesk.com/t5/Installation-Licensing/NET-Framework-Cleanup-Tool-for-Unhandled-Except...

Good Luck!