problem loading anything from win7 64 to r3

I just received my r3 and I try to load something but I get always a message : avrdude: ser_send(): write error: sorry no info avail.

My system is a win 7 64. I see arduino on com5. when I try to update the driver it says that already updated at best I tried the loop back (,73748.0.html) and I don't get any character back. When I connect arduino I get the beep from win as for any new usb device. When I list usb devices I don't see arduino, but listing all devices and printers arduino on com 5 appears

What can I do?

I just fixed it: the problem was with my pc usb port. By changing it to an inhouse port it worked fine.