使用NuGet安装EntityFrameWork4.2
1、下载NuGet
有两种方式下载NuGet
第一种：在微软的档案库下载，下载地址为：http://visualstudiogallery.msdn.microsoft.com/27077b70-9dad-4c64-adcf-c7cf6bc9970c?SRC=VSIDE
弟二种：在vs2010的Tools中Extension Manager-》OnlineGallery 中搜索NuGet并下载安装
2、安装NuGet
在安装NuGet时，遇到了一个错误
Error: The Package Manager Console requires PowerShell 2.0 runtime, which is not detected on this machine.
Please install the PowerShell 2.0 from http://support.microsoft.com/kb/968929 and restart Visual Studio.
解决方案：卸载PowerShell 1.0
卸载后，能正确的安装成功
3、安装EntityFramework4.2
在 Package Manager Console 中 运行Install-Package EntityFramework
遇到错误
Install-Package : The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel.
At line:1 char:16
+ Install-Package <<<< EntityFramework
+ CategoryInfo : NotSpecified: (:) [Install-Package], WebException
+ FullyQualifiedErrorId : NuGetCmdletUnhandledException,NuGet.PowerShell.Commands.InstallPackageCommand
解决方案：
修改package Source为：http://packages.nuget.org/v1/FeedService.svc/