As an Administrator, you can set the execution policy by typing this into your PowerShell window:
Set-ExecutionPolicy RemoteSigned
For more information, see Using the Set-ExecutionPolicy Cmdlet.
When you are done, you can set the policy back to its default value with:
Set-ExecutionPolicy Restricted
You may see an error:
Access to the registry key
'HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\PowerShell\1\ShellIds\Microsoft.PowerShell' is denied.
To change the execution policy for the default (LocalMachine) scope,
start Windows PowerShell with the "Run as administrator" option.
To change the execution policy for the current user,
run "Set-ExecutionPolicy -Scope CurrentUser".
So you may need to run the command like this (as seen in comments):
Set-ExecutionPolicy RemoteSigned -Scope CurrentUser