mobile

Hi all, title says it all really, I can't connect my tf101 to Windows 7, the PC beeps when I plug it in and that's it, no dialog saying usb device found or anything, I've Googled for hours and tried installing Asus official drivers as well as the recommended Naked ones but zilch works, adb doesn't list any devices and I'm at a loss as to what to try next - any help much appreciated