问题
"This application requires .NET Framework 3.5 SP1. Please install the .net framework then run this installer again"
But the system has already installed .net Framework 4.0. In add remove programs I can see the following two entries:
1: Microsoft .NET Framework 4 Client Profile
2: Microsoft .NET Framework 4 Extended.
Any ideas why the installation is failing?
Update - Repro steps:
XP was installed with SP2.
Installed XP3
Installed IE 8
Installed VS2010 Professional - 10.0.30319
Tried to install EL 5.0 - Failed
The machine has no IIS installed.
回答1:
Aseem, this is surprising since we had a separate test pass done on .NET Framework 4.0. Can you provide more details for us to repro? Which version of OS, 64-bit or 32? Has the system had another version of .NET framework installed which was later removed or is it on a clean .NET4.0 installation?
Feb 5 update
Aseem, we have been able to reproduce the issue. I've logged it on codeplex with a workaround (basically, install .NET3.5 SP1, then EntLib5.0, then uninstall .NET 3.5 SP1). If you don't care for Visual Studio integration, you can freely copy the dlls without running the msi. Thanks again for reporting this.
来源：https://stackoverflow.com/questions/4667206/enterprise-library-5-0-installation-error