Index: /trunk/src/VBox/HostDrivers/Support/win/SUPR3HardenedMain-win.cpp
===================================================================
--- /trunk/src/VBox/HostDrivers/Support/win/SUPR3HardenedMain-win.cpp	(revision 53002)
+++ /trunk/src/VBox/HostDrivers/Support/win/SUPR3HardenedMain-win.cpp	(revision 53003)
@@ -4236,7 +4236,12 @@
                 memcpy(pszErrorInfo, pszPrefix, cchPrefix);
                 pszErrorInfo[cbErrorInfo - 1] = '\0';
+                SUP_DPRINTF(("supR3HardenedWinReadErrorInfoDevice: '%s'", &pszErrorInfo[cchPrefix]));
             }
             else
+            {
                 *pszErrorInfo = '\0';
+                if (rcNt != STATUS_END_OF_FILE)
+                    SUP_DPRINTF(("supR3HardenedWinReadErrorInfoDevice: NtReadFile -> %#x\n", rcNt));
+            }
         }
         else
@@ -4244,4 +4249,7 @@
         NtClose(hFile);
     }
+    else
+        SUP_DPRINTF(("supR3HardenedWinReadErrorInfoDevice: NtCreateFile -> %#x\n", rcNt));
+
     return pszErrorInfo;
 }