Hi floan13. Is there any indication that the drive is powered on when you connect it (if there's a led does it light up, do you feel/hear it spinning etc.)? You should definitely follow ronintexas's advice and try it on a different computer. You should also try different USB cables (not longer than 12").
You could also open up Device Manager -> click on View -> select Show hidden devices -> expand all the nodes by clicking on "+" symbol and if you find any greyed ones right click on them and select Uninstall -> restart the computer and try to connect your drive again.
Hope that helps.