Released in 2009, the Dell OptiPlex 780 Small Form Factor is a mini-desktop computer in Dell's OptiPlex 780 lineup. Identified by the model number DCCY1F.
It could be becouse bad usb port (damaged) or you dont have issues. Check if the pins inside usb port on pc are bent. Check if you have drivers installed in device manager. Most of older pcs have issues with installing usb 3.0 drivers when installing new windows.
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