Dear All, thank you for the previous problem - it was solved. Now there is a another one problem that need your fantastic brain power. Whenever they plug in a portable external HD (2.5" that runs off the USB power), no drive letter for external hard drive is seen in my computer or Windows explorer. All 2.5" drives are recognised as they are seen in disk management, a green ticked arrow in the system tray, I can feel the mechanical HD moving in my hands & it is seen in the bios. I have to right click & use the option change drive letters and paths. Then the HD is seen in my computer & Windows explorer. This is a long way to access a 2.5" HD. But a desktop 3.5" is seen automatically. I have tried all USB 2.0 7 3.0 ports on the computer. All the 2.5" are working fine on my Dell L502x XPS laptop. Thanks to all.