i have inspiron 1420 laptop which comes with 4 usb 2.0. my external harddrive has been consitanly giving me 10mgb/s+ transfer speed. but suddlenly its around 800kb/s. and i get that error too. that lead me to beleive that there was something wrong with the driver but in device manager it says the device driver was installed successfully but fail when running. i dont no how to fix that.