Mr. Roboto

Showstopper

It's Windows PowerShell to the rescue, as Mr. Roboto looks for a way to see what services need restarting.

• By Jeffery Hicks
• 05/01/2008

My first thought was to write an HTML application using VBScript and Windows Management Instrumentation (WMI). Then I realized this is a perfect situation for Windows PowerShell. Once you have some PowerShell fundamentals under your belt, you can solve this challenge without any scripting. You don't have to install PowerShell on your servers -- you can accomplish everything from your Windows XP or Vista desktop.

I'll start with a basic expression and end with a more complete solution. To understand the basics, open a PowerShell session and try this single-line command:

PS C:\> get-wmiobject -query 
"Select * from win32_service 
where startmode='auto' AND state 
!='running'"

If you have any services set to run automatically, but they aren't, you should get something back. I want to reiterate that this isn't scripting: You're using PowerShell as an interactive console. To connect to a remote machine use this:

PS C:\> get-wmiobject -query 
"Select * from win32_service 
where startmode='auto' AND 
state !='running'" -computer "Server01"

To process the list of servers, we'll leverage the PowerShell pipeline, get the content of a text file and pass the contents to our Get-WMIObject cmdlet:

PS C:\> Get-content servers.txt | 
forEach { get-wmiobject -query 
"Select * from win32_service 
where startmode='auto' AND
 state !='running'" -computer $_}

You need administrative permission on the remote servers, but you can specify alternate credentials. The recommended approach is to save the alternate credential as a PowerShell variable and pass it on when needed like this:

PS C:\> $cred=get-credential 
mydomain\administrator

Enter the password in the dialog box. The credential is stored securely within your PowerShell session and erased when it ends. To use the credential, modify the previous expression:

PS C:\> Get-content servers.txt | 
forEach { get-wmiobject -query 
"Select * from win32_service 
where startmode='auto' AND state
 !='running'" -computer $_ 
 -credential $cred}

Remember, you can't use alternate credentials for the local system. If you get several results, you probably can't tell which service goes with which server. All we have to do is give PowerShell some formatting instructions on what to display:

PS C:\> Get-content servers.txt | 
forEach { get-wmiobject -query 
"Select * from win32_service 
where startmode='auto' AND 
state !='running'" -computer $_} | 
Format-Table 
SystemName,Name,Displayname

While this should solve Tom's initial request, I've gone ahead and created a filtering function called Show-Stopped. You can run this function on the local machine like this:

PS C:\> show-stopped
ExitCode  : 0
Name      : LVSrvLauncher
ProcessId : 0
StartMode : Auto
State     : Stopped
Status    : OK

Because the function writes a Win32_Service object to the pipeline, you can access any of its properties. This example will give you a nicely formatted report. This function can also use an alternate credential, although you'll have to create it ahead of time, and it will use it for every server it processes:

PS C:\> cred=get-
credential "domain\admin"
PS C:\> get-content servers.txt | 
show-stopped $cred | Format-List 
SystemName,Name,State

Each server in servers.txt is piped to the function and makes a WMI connection with the alternate credential. The output is piped to Format-List. Because objects are coming out of the pipeline, you can write them to a file, send them a printer, format as HTML, e-mail or export.

Once you spend a little time with PowerShell, you'll quickly realize its value. I certainly hope my new friend Tom does as well.