Index: pnpmgr.c
===================================================================
--- ntoskrnl/io/pnpmgr/pnpmgr.c	(revision 74003)
+++ ntoskrnl/io/pnpmgr/pnpmgr.c	(working copy)
@@ -1996,29 +1996,29 @@
                               &IoStatusBlock,
                               IRP_MN_QUERY_ID,
                               &Stack);
-   if (NT_SUCCESS(Status))
+   if (!NT_SUCCESS(Status))
    {
-      /* Append the instance id string */
-      wcscat(InstancePath, L"\\");
-      if (ParentIdPrefix.Length > 0)
-      {
-         /* Add information from parent bus device to InstancePath */
-         wcscat(InstancePath, ParentIdPrefix.Buffer);
-         if (IoStatusBlock.Information && *(PWSTR)IoStatusBlock.Information)
-            wcscat(InstancePath, L"&");
-      }
-      if (IoStatusBlock.Information)
-         wcscat(InstancePath, (PWSTR)IoStatusBlock.Information);
+      DPRINT("IopInitiatePnpIrp() failed (Status %x)\n", Status);
+      IoStatusBlock.Information = 0;
+   }
 
-      /*
-       * FIXME: Check for valid characters, if there is invalid characters
-       * then bugcheck
-       */
-   }
-   else
+   /* Append the instance id string */
+   wcscat(InstancePath, L"\\");
+   if (ParentIdPrefix.Length > 0)
    {
-      DPRINT("IopInitiatePnpIrp() failed (Status %x)\n", Status);
+      /* Add information from parent bus device to InstancePath */
+      wcscat(InstancePath, ParentIdPrefix.Buffer);
+      if (IoStatusBlock.Information && *(PWSTR)IoStatusBlock.Information)
+         wcscat(InstancePath, L"&");
    }
+   if (IoStatusBlock.Information)
+      wcscat(InstancePath, (PWSTR)IoStatusBlock.Information);
+
+   /*
+    * FIXME: Check for valid characters, if there is invalid characters
+    * then bugcheck
+    */
+
    RtlFreeUnicodeString(&ParentIdPrefix);
 
    if (!RtlCreateUnicodeString(&InstancePathU, InstancePath))