PowerShell Script to get Memory\Available MBytes

Question

I have a SQL Agent job with 3 separate Operating System Command Steps.
PowerShell.exe Get-Date
PowerShell.exe Get-Counter "\\mmserver\Memory\Pages/sec" | Format-table -auto
PowerShell.exe Get-Counter "\\myserver\Memory\Available MBytes" | Format-Table -auto
The first two steps work fine.  The third fails.  I have tried reformatting the counter name in any number of ways including escaping the backslashes, adding single quotes around various pieces, and I tried creating a string variable for the counter
name.
The failure message varies a little depending on what I change but basically it seems to be trying to interpret "MBytes" as a separate parameter.  For example:
The error information returned by PowerShell is: 'Get-Counter : A positional parameter cannot be found that accepts argument 'MBy  '
Followed immediately in the log file with a second error on the remainder of the command string.
The error information returned by PowerShell is: 'tes'.  At line:1 char:12  + Get-Counter <<<< 
\\myserver\Memory\Available MBytes      + CategoryInfo          : InvalidArgument: (:) [Get-Counter], ParameterBindingException    '
Other errors indicate the name of the counter is wrong in someway.  For example, I found I had to include the server name even though the script is running locally and it works find from the ISE.
I appreciate any assistance :)
Ray

Answer 1

Here's what worked for me from a command prompt, though I'm not sure why you were seeing that behavior when the value appeared to be quoted properly. Maybe cmd.exe and/or SQL Server was stripping the quotes before sending the string to PowerShell.exe:
PowerShell.exe "Get-Counter '\\myserver\Memory\Available MBytes' | Format-Table -auto"