Index: /trunk/src/VBox/Main/src-server/MachineImpl.cpp
===================================================================
--- /trunk/src/VBox/Main/src-server/MachineImpl.cpp	(revision 36016)
+++ /trunk/src/VBox/Main/src-server/MachineImpl.cpp	(revision 36017)
@@ -1316,5 +1316,5 @@
     AutoWriteLock alock(this COMMA_LOCKVAL_SRC_POS);
 
-    /* We cant go below the current number of CPUs if hotplug is enabled*/
+    /* We cant go below the current number of CPUs attached if hotplug is enabled*/
     if (mHWData->mCPUHotPlugEnabled)
     {
@@ -1323,5 +1323,6 @@
             if (mHWData->mCPUAttached[idx])
                 return setError(E_INVALIDARG,
-                                tr(": %lu (must be higher than or equal to %lu)"),
+                                tr("There is still a CPU attached to socket %lu."
+                                   "Detach the CPU before removing the socket"),
                                 CPUCount, idx+1);
         }