How can I install Arduino MEGA 2560 in Windows 7 ?

Hi everybody

I bought an Arduino MEGA 2560 and I can't install that in Windows 7 (32bit)

My arduino board picture :

IDE tools menu and Configures :

The device manager and USB port situation :

After upload source error message :

And I tried to install USB drive with Update Driver in path " F:\Programs\Arduino\drivers " but windows could not install the drive and did not find any driver in this path ...

I am really confused ,,,,