The easiest way to open an admin Powershell window in Windows 10 (and Windows 8) is to add a "Windows Powershell (Admin)" option to the "Power User Menu". Once this is done, you can open an admin powershell window via Win+X,A or by right-clicking on the start button and selecting "Windows Powershell (Admin)":
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Here's where you replace the "Command Prompt" option with a "Windows Powershell" option:
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