Why does pyinstaller exe not run in windowed mode but fine without it? I have changed over to a windows OS from Linux. Never had any issue before hand, how do I correct this.

IHO don’t use windowed mode, rather suppress output if you have to.

If you insist on using it, Read this.

In other words:

import sys
import subprocess
from PyQt4 import QtGuidef verify_license():tmp_file = '.license_output'try:with open(tmp_file, 'w+') as file_obj:proc = subprocess.Popen(['echo', 'hi'], shell=True,stdout=file_obj, stderr=subprocess.STDOUT,stdin=subprocess.PIPE)ret = proc.wait()if ret != 0:sys.exit(-1)with open(tmp_file, 'r') as file_obj:output = file_obj.read()except Exception as err:sys.exit(-1)if 'hi' not in output:raise Exception('bad news: output was %s' % (output))def main():app = QtGui.QApplication(sys.argv)w = QtGui.QWidget()w.resize(250, 150)w.move(300, 300)w.setWindowTitle('Simple')w.show()sys.exit(app.exec_())if __name__ == '__main__':verify_license()main()

I still do not recommend this approach however. Redirect or suppress stdout is much better.