My 2TB external harddisk usb2.0 cannot use ? 3.0 can use. why?

WD External Drives External Drives for PC
1

my 2TB external harddisk usb2.0 cannot use ?? 3.0 can use.  why?

2

Is your computer USB 3.0 compatible?

Joe

3

yes, but frist time i plug in is usb 2.0, running is ok, after second time plug to usb 2.0 cannot use already, tell me usb device not recognized.