I did a quick (<3min) video showing how to schedule a PowerShell script with the Windows Task Scheduler. Quick note, Assuming you are running a SharePoint related PowerShell, don't forget two things: One, you'll need to include

Add-PSSnapin Microsoft.SharePoint.PowerShell -ErrorAction SilentlyContinue

Also when Saving the script and entering a user account and password – don’t forget this account must have rights to SharePoint.