mstask: Implemented DllUnregisterServer.
diff --git a/dlls/mstask/mstask_main.c b/dlls/mstask/mstask_main.c
index 53c3449..c7b3dea 100644
--- a/dlls/mstask/mstask_main.c
+++ b/dlls/mstask/mstask_main.c
@@ -155,3 +155,8 @@
 {
     return register_mstask(TRUE);
 }
+
+HRESULT WINAPI DllUnregisterServer(void)
+{
+    return register_mstask(FALSE);
+}