I cannot install Flash Player

......not even through the alternative link given for installation problems. I have repeatedly tried....when I click 'OK' on 'Open Executable File?' nothing happens.

UPDATE

I have now installed an archive zip version 19.0.0.245

But when I click 'Check Now' for Updates in Flash Player Settings Manager nothing happens.

Windows XP SP3 / Firefox ESR 38.5.2 / Flash Player Version 20.0.0.235.

Please help.