diff --git a/CHANGELOG b/CHANGELOG
index 805cb544d..e1e178cce 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -64,6 +64,12 @@ Until now #$ reader macro accepted simple vectors as an argument, what lead
 to bugs if vector didn't match specific requirements like the element type
 or the arity. Now we sanitize this.
 
+- thread fix on msvc: on windows importing thread was closing the thread
+handler so the thread wakeup wasn't working because the handler is not more valid.
+
+- import thread wasn't set upping a proper environment: on some case
+the thread was mistakenly thinking that the thread was already registered.
+
 * 16.1.2 changes since 16.0.0
 
 ** API changes
diff --git a/msvc/c/Makefile b/msvc/c/Makefile
index 15bd498bc..656f2f210 100755
--- a/msvc/c/Makefile
+++ b/msvc/c/Makefile
@@ -66,7 +66,7 @@ HDIR	= $(top_srcdir)\h
 HFILES	= ..\ecl\config.h ..\ecl\atomic_ops.h $(HDIR)\ecl.h $(HDIR)\ecl-cmp.h\
 	$(HDIR)\object.h $(HDIR)\cs.h $(HDIR)\stacks.h\
 	$(HDIR)\external.h $(HDIR)\cons.h $(HDIR)\legacy.h\
-	$(HDIR)\number.h $(HDIR)\page.h
+	$(HDIR)\number.h $(HDIR)\page.h \
 	$(HDIR)\internal.h $(HDIR)\ecl-inl.h $(HDIR)\bytecodes.h \
 	$(HDIR)\impl\math_dispatch.h
 
diff --git a/src/c/main.d b/src/c/main.d
index 3841005d7..981da13c0 100755
--- a/src/c/main.d
+++ b/src/c/main.d
@@ -201,7 +201,7 @@ _ecl_dealloc_env(cl_env_ptr env)
     ecl_internal_error("Unable to deallocate environment structure.");
 #else
 # if defined(ECL_USE_GUARD_PAGE)
-  if (VirtualFree(env, sizeof(*env), MEM_RELEASE))
+  if (!VirtualFree(env, sizeof(*env), MEM_RELEASE))
     ecl_internal_error("Unable to deallocate environment structure.");
 # endif
 #endif
diff --git a/src/c/threads/process.d b/src/c/threads/process.d
index 0b818f397..a53b0ea07 100755
--- a/src/c/threads/process.d
+++ b/src/c/threads/process.d
@@ -339,14 +339,16 @@ ecl_import_current_thread(cl_object name, cl_object bindings)
 #ifdef ECL_WINDOWS_THREADS
   {
     HANDLE aux = GetCurrentThread();
-    DuplicateHandle(GetCurrentProcess(),
-                    aux,
-                    GetCurrentProcess(),
-                    &current,
-                    0,
-                    FALSE,
-                    DUPLICATE_SAME_ACCESS);
-    CloseHandle(current);
+    if ( !DuplicateHandle(GetCurrentProcess(),
+                          aux,
+                          GetCurrentProcess(),
+                          &current,
+                          0,
+                          FALSE,
+                          DUPLICATE_SAME_ACCESS) )
+    {
+	   return 0;
+    }
   }
 #else
   current = pthread_self();
@@ -369,7 +371,7 @@ ecl_import_current_thread(cl_object name, cl_object bindings)
   {
     cl_object processes = cl_core.processes;
     cl_index i, size;
-    for (i = 0, size = processes->vector.dim; i < size; i++) {
+    for (i = 0, size = processes->vector.fillp; i < size; i++) {
       cl_object p = processes->vector.self.t[i];
       if (!Null(p) && p->process.thread == current)
         return 0;
@@ -407,6 +409,10 @@ void
 ecl_release_current_thread(void)
 {
   cl_env_ptr env = ecl_process_env();
+#ifdef ECL_WINDOWS_THREADS
+  HANDLE to_close = env->own_process->process.thread;
+#endif
+
   int cleanup = env->cleanup;
   thread_cleanup(env->own_process);
 #ifdef GBC_BOEHM
@@ -414,6 +420,9 @@ ecl_release_current_thread(void)
     GC_unregister_my_thread();
   }
 #endif
+#ifdef ECL_WINDOWS_THREADS
+  CloseHandle(to_close);
+#endif
 }
 
 @(defun mp::make-process (&key name ((:initial-bindings initial_bindings) ECL_T))
diff --git a/src/cmp/cmpmain.lsp b/src/cmp/cmpmain.lsp
index 0b8bbfdfe..2a1568fbf 100755
--- a/src/cmp/cmpmain.lsp
+++ b/src/cmp/cmpmain.lsp
@@ -73,7 +73,7 @@ the environment variable TMPDIR to a different value." template))
 
 #+msvc
 (defun delete-msvc-generated-files (output-pathname)
-  (loop for i in '("implib" "exp" "ilk" "pdb")
+  (loop for i in '("implib" "exp" "ilk" )
         for full = (make-pathname :type i :defaults output-pathname)
         for truename = (probe-file full)
         when truename