Check your screen settings. It seems the installer is simply unable to determine your screen size and DPI and renders the dialog incorrectly. If you have modified any of that stuff, revert to default settings. Otherwise try to enforce a specific "safe" resolution liek standard HD (1920 x 1080) and see if it works. Once installed you can always revert back to what you had before.
Thanks both of you for your reply but sadly i'm still facing the same problem. I've followed your advice (like resetting display settings, scaling resolution low to high, also tried tweaking some property settings ) but still can't seeing the installer button.