I have a dell xps 720 the dell express service tag (7CDK2D1) Says that the pc in actually a XPS 710. these two do not have the same bios. The Pc will not boot with and usb install (i:e Logitech unifying receiver). internal usb ports boot without issue. I currently cant load any bios i receive a communication error or i/o disk error. I load ubuntu from a separate HDD and windows 7 and neither platform could load. I have tried from a SD card from the memory card reader but it will not boot from and SDcard. Does anyone have any other suggestions. CN-0U723D-13740-05D-001A the the full part number on the tag that is on the motherboard and if someone has any suggestions?