diff --git a/source2/Build/Cosmos.Build.Builder/CosmosTask.cs b/source2/Build/Cosmos.Build.Builder/CosmosTask.cs
index 6c9c6aa20..d4f9d9fac 100644
--- a/source2/Build/Cosmos.Build.Builder/CosmosTask.cs
+++ b/source2/Build/Cosmos.Build.Builder/CosmosTask.cs
@@ -129,6 +129,7 @@ namespace Cosmos.Build.Builder {
 
       CheckIsVsRunning();
       CheckVs2010Sp1();
+      CheckVs2010SDK();
       CheckNet35Sp1(); // Required by VMWareLib
       CheckForUninstall("Inno Setup QuickStart Pack", true);
       CheckForInstall("Microsoft Visual Studio 2010 SDK SP1", true);
@@ -153,6 +154,16 @@ namespace Cosmos.Build.Builder {
       }
     }
 
+    void CheckVs2010SDK() {
+      Echo("Checking for Visual Studio 2010 SDK SP1");
+      using (var xKey = Registry.LocalMachine.OpenSubKey(@"SOFTWARE\Wow6432Node\Microsoft\VisualStudio\VSIP\10.0")) {
+        // This tell us if SDK is installed, but not if its SP1. But if CheckVs2010Sp1() passed, then it should be SP1.
+        if (xKey.GetValue("InstallDir") == null) {
+          throw new Exception("Visual Studio 2010 SDK not detected.");
+        }
+      }
+    }
+
     void WriteDevKit() {
       Section("Writing Dev Kit to Registry");