How to install Enterprise Library 5.0?

When I try to do it I get the error "The application requires .NET Framework 3.5 SP1." I have .NET 4.0, how do I insta开发者_开发百科ll 3.5 SP1? Can I have both?

Feel free to install all versions of .Net. They will not interfere with each other!

For adding dependencies to your project I recommend NuGet. Really handy and makes the project clean by adding references into it instead of requiring additional installation packages.

.Net 4.0 projects are capable of using .Net 2.0, .Net 3.0 and .Net 3.5 libraries. But note that projects running under ".Net 4.0 Client Profile" can have problems doing this, and you only get a misleading error when attempting to run the project. From within Visual Studio everything seems right.

Just like Tedd Hansen says you can sure have as many .NET versions as you want in your computer for it creates no conflict at all. I take it you are just trying to install something. If that's the case then you can always use this link to download the bootstrapper that will determine the right 3.5 verison for you (x86 or x64) and download and install it.

If you are developing an application you can change the target framework of the project by going to the project properties page and, in the compile tab, click on the "Advanced Compile Options" button. There you'll be able to choose.

And, also as Tedd mentions, you should avoid targeting the "Client Profile" versions unless you specifically know that the subsets present therein are sufficient.

On my machine (Windows 7 Enterprise x86) I have installed .Net framework 4.0 and Enterprsie Library 5.0 without any problems. Maybe some other issue you're facing?

IAdapter, I've answered this already. See my answer and the workaround in the comment dtd Feb 5, 2011.