You can find old versions of Firefox bundled with old versions of Flash Player.
Firefox is open source and this kind of redistribution is completely legal. As for Flash, this might be illegal or it might be gray area (illegal but tolerated) as happens with most abandonware, or even legal (fair use for research?). Laws are different in different jurisdictions ...
1.Try pressing Alt+Enter multiple times till it changes to full screen.
2.If this doesn't work press f11 once then press the maximise button (present near the close button. Just like any other window) and press f11 again.
These should work.