tablet usb power

hi and thanks im new to this site but for four weeks have had no luck anywhere. i won a dell latitude 10-st2e tablet with windows 8 at an auction. since it had no charger they could not test it i bought it as is. i bought the charger and when charged it turned on only to be admin password in...

I've got a Dell Venue 11, 7130, with a fresh install of Windows 8.1. I've configured it not to sleep or hibernate, and disabled power management on USB ports. However, when the screen shuts off (Inactivity timeout, or I shut the 'lid' (When docked with it's keyboard), the USB port powers down...