diff --git a/finalcif/tools/process.py b/finalcif/tools/process.py
index 82ab83d7..610a193e 100644
--- a/finalcif/tools/process.py
+++ b/finalcif/tools/process.py
@@ -39,6 +39,8 @@ def run_process(self):
         threading.Thread(target=self._monitor_output_log).start()
         # self.process.readyReadStandardOutput.connect(self.on_ready_read)
         self.process.finished.connect(self._onfinished)
+        if sys.platform.startswith('win'):
+            self.process.setCreateProcessArgumentsModifier(self.hide_window)
         self.process.setWorkingDirectory(str(self.cif_file.parent))
         self.cif_file.with_suffix('.chk').unlink(missing_ok=True)
         self.process.start(self.platon_exe, ["-U", str(self.cif_file.name)])
@@ -85,6 +87,11 @@ def _parse_chk_file(self):
             if line.startswith('# Z'):
                 self.Z = line[19:24].strip(' ')
 
+    def hide_window(self, args):
+        # This needs Windows
+        args[0] = args[0] | 0x08000000  # CREATE_NO_WINDOW flag
+        return args
+
     @property
     def platon_exe(self):
         if sys.platform.startswith('win'):