NANT 0.92 SDK 7 not found

Wednesday:

Windows 2008 R2 64Bit SDK installed on C: \ Program Files (x86) \ Microsoft SDK \ Windows \ v7.1

The frame is installed on C: \ Windows \ Microsoft.NET \ Framework64 \ v4.0.30319

Trying to run Nant to compile some .NET 4 classes, and we get the following message.

The SDK for the 'net-4.0' framework is not available or not configured.:

            NAnt.Core.BuildException: The SDK for the 'net-4.0'
framework is not available or not configured.
               at NAnt.Core.Tasks.ExternalProgramBase.DetermineFilePath()
               at NAnt.Core.Tasks.ExternalProgramBase.get_ProgramFileName()
               at
NAnt.Core.Tasks.ExternalProgramBase.PrepareProcess(Process process)
               at NAnt.Core.Tasks.ExternalProgramBase.StartProcess()
               at NAnt.Core.Tasks.ExternalProgramBase.ExecuteTask()
               at NAnt.Core.Task.Execute()
               at NAnt.Core.Target.Execute()
               at NAnt.Core.Project.Execute(String targetName, Boolean
forceDependencies)
               at NAnt.Core.Project.Execute()
               at NAnt.Core.Project.Run()

Looking at the NANt.exe.config file, it seems that it looks to find a suitable path for the SDK.

<project>
 <readregistry
     property="installRoot"
      key="SOFTWARE\Microsoft\.NETFramework\InstallRoot"
      hive="LocalMachine" />
 <locatesdk property="sdkInstallRoot"
 minwinsdkver="v7.0A" minnetfxver="4.0" maxnetfxver="4.0.99999"
 failonerror="false" />
</project>

The key does not exist in the registry, and our SDK version does not match minwinsdkver = "v7.0A"

Does anyone encounter this problem and discover the correct operation?