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Running .net 3.5 application on .net 4.0 RRS feed

  • Question

  • Hello,

    We have an application that's targeting .net 3.5. This means customers must have .net 3.5 installed. In the case where they have .net 4.0 installed (which is now automatically installed on new servers?), it doesn't work and they have to uninstall .net 4.0, then install all the way up to .net 3.5. But I noticed something strange, on my dev machine i only have .net 4.0 installed, not .net 3.5, and the application works fine on my machine. Why is this? Is there any way to allow our .net 3.5 application to run on .net 4.0 without the customer having to uninstall and install?

    Also, I assume to install a .net version you have to have the previous version installed. So that means if you have .net 4.0 installed, you have to uninstall it, then install .net 2.0, .net 3.0, then .net 3.5. Is this true?

    Thanks


    http://compasstechnologies.com
    Monday, June 27, 2011 5:35 PM

Answers

  • .NET Framework 1.1 was not part of Windows and had to be installed separately, that's why you see it in your installed programs list.

    What Windows version on your dev machine? Windows 7, by any chance?

    If so, Control Panel->Programs and Features->Turn Windows features on and off...

    In the Windows Features dialog, you find "MIcrosoft .NET Framework 3.5.1" That means .NET Framework 2.0/3.0/3.5 through 3.5 SP1 is an integral part of your OS.

    FWIW, Vista comes with .NET Framework 2.0/3.0.

    If you are dealing with earlier Windows versions, all needed frameworks must be installed.

    For the 2.0/3.0/3.5, the best way to go is with this cumulative update installer once you have 2.0:

    http://download.microsoft.com/download/2/0/e/20e90413-712f-438c-988e-fdaa79a8ac3d/dotnetfx35.exe

    • Proposed as answer by Alexander Sun Wednesday, June 29, 2011 5:13 AM
    • Marked as answer by Makolyte Wednesday, June 29, 2011 1:39 PM
    Monday, June 27, 2011 11:42 PM

All replies

  • No, you don't have to remove .NET Framework 4.0 in order to install .NET Framework 2.0/3.0/3.5. THey are separate full frameworks and exist side by side on a single PC.

    A clarification: .NET Framework 2.0/3.0/3.5 are all ONE framework. 2.0 is the base, full, framework while 3.0 and 3.5 are extensions of 2.0.

    I'm a bit curious about a couple of things you said: .NET Framework 4.0 installed on new servers? What Windows version are you talking about? The latest (Win 7 and WS 2008 R2) come with .NET Framework 2.0/3.0/3.5 through 3.5 SP1 as an integral part of the OS. .NET Framework 4.0 does NOT come as an integral part of any Windows version, AFAIK.

    So, before we start talking about installing 2.0, etc. please tell us what Windows version(s) you are talking about.

     

    Monday, June 27, 2011 8:10 PM
  • Oh i didn't know they were considered one framework. That's good news, less work for the customer.

     

    I'm not sure which server they're on. Something strange though is that on my dev machine I have .net 1.1 (or whatever) and .net 4.0. This is based on looking at Add/Remove Programs, not looking in the registry. So it looks like i don't have .net 3.5, and our product still works on my machine. How is that?


    http://compasstechnologies.com
    Monday, June 27, 2011 8:32 PM
  • .NET Framework 1.1 was not part of Windows and had to be installed separately, that's why you see it in your installed programs list.

    What Windows version on your dev machine? Windows 7, by any chance?

    If so, Control Panel->Programs and Features->Turn Windows features on and off...

    In the Windows Features dialog, you find "MIcrosoft .NET Framework 3.5.1" That means .NET Framework 2.0/3.0/3.5 through 3.5 SP1 is an integral part of your OS.

    FWIW, Vista comes with .NET Framework 2.0/3.0.

    If you are dealing with earlier Windows versions, all needed frameworks must be installed.

    For the 2.0/3.0/3.5, the best way to go is with this cumulative update installer once you have 2.0:

    http://download.microsoft.com/download/2/0/e/20e90413-712f-438c-988e-fdaa79a8ac3d/dotnetfx35.exe

    • Proposed as answer by Alexander Sun Wednesday, June 29, 2011 5:13 AM
    • Marked as answer by Makolyte Wednesday, June 29, 2011 1:39 PM
    Monday, June 27, 2011 11:42 PM