我想安装Juice UI，但遇到了复杂的问题。我的操作系统是"Windows seven Ultimate"，我使用的是带有NuGet Package Manager 2.0.30625.9003的Visual Studio 2012和dotNetFrame work 4.5，无论如何，我尝试了Tools>Extension and Updates和命令提示符（PM>Install Package JuiceUI）来安装juice，但在这两种情况下我都得到了这个错误：
**PM> Install-Package JuiceUI
Attempting to resolve dependency 'jQuery (≥ 1.8.2)'.
Attempting to resolve dependency 'jQuery.UI.Combined (≥ 1.9.0)'.
Attempting to resolve dependency 'json2'.
Attempting to resolve dependency 'AmplifyJS'.
Successfully installed 'jQuery 1.8.3'.
Successfully installed 'jQuery.UI.Combined 1.9.2'.
Successfully installed 'json2 1.0.2'.
Successfully installed 'AmplifyJS 1.1.0'.
Successfully installed 'JuiceUI 1.1.1'.
Successfully added 'jQuery 1.8.3' to jame-jam.
Successfully added 'jQuery.UI.Combined 1.9.2' to jame-jam.
Successfully added 'json2 1.0.2' to jame-jam.
Successfully added 'AmplifyJS 1.1.0' to jame-jam.
Successfully uninstalled 'JuiceUI 1.1.1'.
Successfully uninstalled 'AmplifyJS 1.1.0'.
Successfully uninstalled '***json2*** 1.0.2'.
Successfully uninstalled 'jQuery.UI.Combined 1.9.2'.
Successfully uninstalled 'jQuery 1.8.3'.
Install failed. Rolling back...
Install-Package : Could not install package 'JuiceUI 1.1.1'. You are trying to install this package into a project that
targets '.NETFramework,Version=v3.5', but the package does not contain any assembly references that are compatible wit
h that framework. For more information, contact the package author.
At line:1 char:16
+ Install-Package <<<< JuiceUI
+ CategoryInfo : NotSpecified: (:) [Install-Package], InvalidOperationException
+ FullyQualifiedErrorId : NuGetCmdletUnhandledException,NuGet.PowerShell.Commands.InstallPackageCommand**
我想知道是否有人帮我解决这个问题！我想它需要DotNetframeWork 3.5，但正如你所知，3.5不适用于Windows7，Juice UI适用于visual studio 2010及更高版本。所以我完全搞混了，我该怎么办！？
错误消息本身解释了问题-
安装程序包：无法安装程序包"JuiceUI 1.1.1"。您正试图将此程序包安装到目标'.NETFramework，Version=v3.5'
juiceUI在4.0以下不起作用。更改项目设置以使用.Net 4.0