A. To look at other examples on the Internet, you'd think putting this at the top of your script would be the answer:
$ErrorActionPreference = "SilentlyContinue"
Don't do that. Sure, it'll suppress errors in your script—ALL of the errors, even helpful ones about syntax errors and so on. Instead, if you anticipate a cmdlet causing an error such as "file not found" or "could not connect" and you don't want to see the error or deal with it, use the -ErrorAction (or -EA) parameter of that cmdlet:
Get-WmiObject Win32_BIOS -computername localhost,not-online -EA SilentlyContinue
All cmdlets have an -EA parameter. It's part of the <CommonParameters> listed in every cmdlet's help.
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