I installed drivers for freecom mobile drive secure (http://www.freecom.com/Support/Product) on a Dell xps 502x with Windows 7 64bits. After installing, no usb port were working. I uninstalled these drivers but usb was not working. I tried uninstall all dell usb device and reinstall official dells drivers but it's still not working. Computer does'nt have any System Restore Point.