Arduino Uno R3 Cant Sync with my pc / laptop

I just brought an arduino uno r3 borad ,
and i tried to upload the examples code useing Ardunio1.0.5 that i downloaded from this site
the problem is ,

on my device manager , that show i have 2 port (COM) but , i cant change the port option on arduino software , and when i double click on my arduino port (DEVICE MANAGER) it show This device cannot start. (Code 10) The specified request is not a valid operation for the target device.

… sorry for my bad language , this problem make me cant upload code to my board


I have same issue with Genuine Arduino Uno Rev 3...

Tried everything, the driver is installed, seems PC - Device com is the issue.

Help !

Tried alternative Compaq Modem Driver as per:

And still the same Code 10.

Is my unit defective? Is there a way to fix it? I tried 3 different usb cables as well. Grteen light lights up also the orange 'L' LED lights up. But evidently no serial port as the driver is installed but device not working....