Does installing .NET 4.0 Framework replace the previous .NET versions?

I get this question all the time with developers asking if installing .NET 4.0 will replace the existing .NET 3.5 framework on their machine. The answer is NO.

.NET 4.0 framework does not replace or remove the previous .NET frameworks. .NET 4.0 successfully installs side-by-side with previous versions of .NET framework including .NET 3.5, 3.0 or even 2.0.

Also note that using Visual Studio 2010 IDE, you can target your applications to use the framework of your choice, i.e. you can use the same IDE to build .NET 2.0, 3.5 and 4.0 apps on the same machine. You just have to choose your desired framework when creating a new project, as shown below

image

5 comments:

  1. Thanks for this! It really helped.

    ReplyDelete
  2. So 4.0 can co-exist with 3.5 but is 3.5 a requirement?

    I'm fairly sure that 4.0 does not contain everything that 3.5 does. If that's the case then what happens if I develop an application in which I want to use some functionality from 4.0 and some from 3.5?

    Would I then require both 3.5 and 4.0 be installed?

    I'm actually trying to figure out which version of .NET my users have installed so that I know what functionality I can use but that difficult if I have to report every single version.

    ReplyDelete
  3. I think the best wording that needs to be documented is:
    "If you install .NET 4.0, does it include functionality for 1.0, 2.0, 2.5, 3.0, and 3.5 OR do you need to install the previous versions to receive functionality introduced in "

    ReplyDelete
  4. What about framework 1.1 ?
    Thanks
    JAYASON

    ReplyDelete
  5. Your articles it’s very useful for me a lot about the Does installing .NET 4.0 Framework replace the previous .NET versions, and I am completely satisfied with your Blog. All comments and articles are very useful and very good. Your blog is very attention-grabbing. This article is very informative. Thank you for sharing this article.

    ReplyDelete