Enterprise Library 5.0 installation error

"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 w开发者_如何学编程hy 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.

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.