Well, first of all, this tablet doesn't need drivers to work properly. I think you should try to uninstall them, restart your PC and then plug your tablet again to see if your PC detects it. Also, what kind of drivers did you install? Did you get the original ones from
here? If you were using these ones and it's not working with and without drivers, try to change the USB port where you have it plugged. If after that it's still not working (it will probably be the case), I guess you should try to plug it into a different PC (if you have the possibility), to see if it's a problem from your PC or from the tablet.