WMI - Starting and Stopping Services

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Introduction to Starting and Stopping Services

This is the page where I show you how to create a Microsoft WMI script that starts or stops a Windows service on a remote computer. (Other pages deal with controlling process and programs). 

My WMI code employs Win32 Service commands to control the operating system and persuade it to stop or start a named service (Alerter). The benefit of learning this Win32 method is that you can adapt it to other Windows services, for example, to start and stop Exchange services.

Topics for Starting and Stopping Services

• Scenario for Starting and Stopping Services
• Example 1 - WMI Script to List the Services running on Computer
• WMI Tutorial - Learning Points
• Example 2 - WMI Script to Stop, then Start a Windows Service
• Listing and Terminating Processes (not Services) - See more here
• Starting Processes (not Services) - See Here
• Summary of WMI to Start / Stop a Windows Service

Key WMI words: Win32 Process

Scenario for Starting and Stopping Services

Let me begin with a reminder.  WMI and VBScripts just mimic what you could do manually.  Therefore, the advantage of a WMI script is that it saves time and gives you the power of controlling other computers from the comfort of your chair.  For example, here is a classic script to restart the remote registry service remotely.

Example 1 - WMI Script to List the Services running on Computer

As promised, we are going to create a script to start or stop Windows services, but to begin with, I want to list merely the services.  (Alerter, Netlogon, Pop3Svc etc).  My reasoning is to build up gradually, and also to provide a script to help us troubleshoot.  For instance, the main WMI script may fail because we type in the wrong name for the service, by getting a list we can be sure to spell the name of the Windows service correctly.

Prerequisites

The Win32_Service Class works for most clients, XP, W2K, even NT 4.0 and Win 9x.

Instructions for Creating your WMI Script

1. Copy and paste the example script below into notepad or a VBScript editor.
2. Which machine on your network do you wish to check?  Change line 15:
   strComputer = "." means, local machine.
3. Save the file with a .vbs extension, for example: Service.vbs 
4. Double click Service.vbs and check the list of Services.  I know it's eccentric that you only get a list from 'N' to 'Z'.  However, there are two reasons for this, firstly a complete list of A-Z would go off screen, secondly, I will let you into a secret, I was troubleshooting the why pop3svc would not work.  The answer was that services are case sensitive, it should have been Pop3Svc not pop3svc.

WMI Script to List Services

WMI Tutorial - Learning Points

From a WMI perspective

1) If you are experienced with WMI, then the two features concentrate on are, Win32_Service and objService.name.

2)  If you are new to WMI then you will soon appreciate that all WMI scripts begin by employing winmgmts to access the root of the CIM library :
Set objWMIService = GetObject("winmgmts:" & strComputer & "\root\cimv2")

2) WMI often requires security clearance in order to query the other machine's hardware, this is why we add :  & "{impersonationLevel=impersonate}!\\" _  

3) Set colComputer = objWMIService.ExecQuery _ is a standard WMI phrase to prepare for the WQL command:  Select * from Win32_Service
".  The part we are particularly interested in is _Service.  Win32 has dozens of properties, here we need to query not the process, but the Service component.

From a VBScript perspective

4) What makes scripting so powerful is the speed with which VBScript loops through an array of objects or properties, in this instance the code to look out for is: For Each....In... Next. 

5)  I am particularly proud of the this command:strServiceList = strServiceList & vbCr & objService.name.  In scripting terms it's primitive, almost a non-entity, but to me it makes the output easier to read.

6) The only property of objService that we are interested in is, .Name. However, we could have substituted other properties, for example .State or .Status.

7) As I discussed at the outset, I deliberately decided to only display a subset of all possible services, I chose to filter with the command, If UCase(Left(objService.name,1)) >"N" then...  Incidentally, there is hardly a script that cannot be fine-tuned with an, If ... Then.. End If. statement.

8)  You could take a different road and output the service information to a file.  VBScript has all the tools you need to create a file and write a service on each line.  In that example, you would not need the If..Then filter.

Example 2 - WMI Script to Stop, then Start a Windows Service

Of all my WMI scripts, this Stop / Start service example benefits most from you tweaking various lines of code.  Let me explain my dilemma.  I wanted to show you how to both start and stop a service.  However, on a production script you may not want to restart the service; you may just want to either start, or stop the service; if so experiment by ' Rem out either objService.StartService() or objService.StopService().  Line 24 - 26.

To take another example of how to customize my script, Alerter is a boring, but safe service to experiment with, so why not substitute another service for Alerter?  However, be careful and remember to leave the machine as you found it.  Learn from my mistakes! I once stopped the TCP/IP NetBIOS helper services with disastrous consequences to the machines connectivity.

Prerequisites

Special note: Make sure that Alerter Service is set to Manual or Automatic.  Check with Services Administrative Tools as necessary.

The Win32_Service Class works for most clients, XP, W2K, even NT 4.0 and Win 9x.

Instructions for Creating your WMI Script

1. Copy and paste the example script below into notepad or a VBScript editor.
2. Which machine on your network do you wish to check?  Change line 15:
   strComputer = "." means, local machine.

WMI Tutorial - Learning Points

From a WMI perspective

1)  As you get to know me, you will realize that I love variables.  This script gave me a real challenge, I wanted to introduce strService so that I could change easily from the boring Alerter to the more useful Pop3Svc, here is the difficulty,
("Select * from Win32_Service Where Name =" & strService & " ").  I solved the problem by precise positioning of the two sets of speech marks, moreover, when I declared strService, it required the syntax " 'Alerter' " and not plain " Alerter ".  Those were trivial points but they can drive you mad if you don't work with VBScript every day.

2) If you are going to adapt this for a production task, then you may need to remove either line 24 objService.StopService() or two lines further down, objService.StartService(). 

However, Efrain D. kindly wrote in and said that he wished to restart, in which case leave in both and possible increase sleep 15000 to 30000, each 1000 is represents a one second delay.

3) I almost forgot, you also need to change strComputer ="." to strComputer = "Victim2 or whichever machine you wish to control.

From a VBScript perspective

4)  As this is a test script, I introduced a delay with WScript.Sleep, the values are in mille seconds so 15000 are just 15 seconds.

5) Even though there is only one computer, the script still needs the loop: For Each....In... Next.  Believe me, I tried to simplify the script by removing the loop, but all I got was an object required error.

Summary of WMI to Start / Stop a Windows Service

This script gives the full flavour of what WMI can achieve.  It gives you control over a distant machine, and also gives you an insight into the possible services that you could start or stop.  There are plenty of VBScript challenges: For... Each ...In ... Next loops; filters with If..then ... End if.  I also have concrete examples of Win32 properties.

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See Also

• Listing Process - See this page
• Starting a Process - See this page
• Terminating a Process - See this page
• WMI Home