Nuget TFS Build issue

HI I am trying to run a TFS automated build and I am getting the following error in one of the projects 

The command "..\..\Tools\NuGet Install ..\Packages.config -o ..\..\Packages" exited with code 3. [C:\...\...\XYZ.vbproj]

I have tried adding a target like below

<Target Name="Build">
    <Exec Command="$(BuildPath)/../../../Tools/Nuget.exe Install $(BuildPath)/../../.../packages.config -o $(BuildPath)/../../Packages" />
  </Target>

but that's not working.I dont know that target is even called from the TFSBuild.proj file. when i call the target from cmd prompt i get this msg

  "All packages listed in packages.config are already installed."

I dont know what "exited with code 3" actually means and what i need to fix. Any suggestions?