Help! please. Unable to access remote system. The following script used. Computer is in a workgroup. Script from DonJ's Powershell 2.0 book
> $c = Get-Credential -credential "MyComputer\Administrator"
> Start-Psjob -command "Get-Service" -computername "MyComputer" -credential $c

get the error:
SessionId       Name            State           HasMoreData     Command
---------       ----            -----           -----------     -------
21                              Failed          False           Get-Service

(I moved your message into the 2.0 forum).

Make sure you have winrm running for starters (start-service winrm) locally and remotely. winrm isn't set to start automatically by default.