Hi Budu,
May 24, 2014 - Select 'Universal Serial Bus controllers'. The Intel USB 3.0 eXtensible Host Controller device and Intel USB 3.0 Root Hub device should be. Downnload Acer Aspire A315-51 laptop drivers or install DriverPack Solution software for driver update. Intel(R) USB 3.0 Host Controller Adaptation Driver.
Welcome to Microsoft community forums. I would appreciate if you could answer the following questions:
What is the model number for Acer computer?
Do you remember making any changes on the computer prior to the issue?
You may face this issue if USB controllers are corrupted. In addition on Jim suggestion I would suggest you to follow these steps:
Step 1: Uninstall and reinstall the USB driver for the computer. Follow the steps:
Press Windows and X together and select Device Manager.
Locate the Universal Serial Bus Controller and expand the driver icon.
Right Click on all the USB driver icon and select Uninstall.
Restart the computer. After restarting the computer, USB driver will automatically be installed.
Connect the external hard drive and test the issue.
Step 2: If the issue still persists, I would suggest you to download and install the latest available chipset driver from Acer support for your model and verify the results. You may also refer to the link to do so.
Usb Serial Controller Driver Rar
Download and install drivers
Hope this helps. If you need further assistance with Windows, let us know and will be glad to help.