Ezine 199 - PowerShell Set-Service
Ezine 199 - PowerShell Manages Windows Services
This week I have multiple objectives. My main aim is to
persuade people to follow my lead - abandon VBScript and take-up PowerShell.
My secondary objective is to remind you that PowerShell has more verbs than
just 'Get'; in this ezine we will employ, Set, Start, Stop and Restart. One
minor learning point, once you seek more active commands than 'get', you
will need to click 'Run as Administrator' before you launch PowerShell
ISE.
Topics for PowerShell Set-Service
♣
As you may already know, I have a phobia of anti-virus software; whilst
troubleshooting a colleague's machine I
could not turn off the AVG program. Then I remembered Windows Services.
Lo-and-behold, this program had installed itself as a service, and was with
great joy that I used a
PowerShell command to disable it. I could have used the operating
system's services GUI, but
scripting was a calming antidote to my anger with a tricky problem.
My main mission this week is to lure people away from VBScript and
tempt them to use PowerShell instead. Once I decided to abandon VBScript and take-up
PowerShell I have never looked back. However, I admit that I was never a VB or
ASP developer, just a dabbler in VBScript for logon scripts and related
tasks.
As a vehicle for our mission I have chosen Windows Services because they
are particularly suitable for my secondary agenda, which is to introduce more
PowerShell verbs, for example, set, start, stop
or restart-service.
A Simple Script to List a Computer's Services
Get-Service
# Also try removing the # on the next line
# Get-Service -ComputerName YourOtherMachine
Note 1: You can check the status, and startup
values, for a named services thus:
get-Service Spooler.
Research Properties of Get-Service by Appending | Get-Member
get-Service | get-Member -memberType Property
Real-life Lessons from Windows Services
It may seem that we are just bumbling about with these Windows Services,
however, if we are observant then we can gather useful knowledge, for
example get-Service reveals that Window 7 no longer has the Alerter or
Messenger services. Also try: get-Service WinRm, it
will check whether Windows
Remoting has been installed.
What is even more instructive is the relationship between the properties
'DisplayName' and 'Name'. My point is that when it comes to scripting
you need to pay special attention of different values, for example try this:
get-service PRINT spooler |ft name, DisplayName. Learn from my mistake,
I thought its name was Print Spooler, and its description was Spooler.
This was doubly wrong. The name is 'spooler', and for once there is no
description property!
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Find More PowerShell Verbs to Compliment Noun Service
Once you discover a PowerShell noun such as service, it's interesting to
research which verbs are associated with it, I use this format: get-command
-noun service. Incidentally, PowerShell nouns are invariably singular,
hence service works, but not serviceS.
get-Command -noun Service
See more on
Get-Service
The point of this script is that you cannot start a service whose 'StartupType'
is disabled, but you can use PowerShell to change it's value to 'Automatic'.
It would be a trivial task to then add a line saying: start-Service
$CompSrv.
# PowerShell Set-Service Example
$CompSrv
="Spooler"
Set-Service $CompSrv -StartupType Automatic
Note 2: Error Message When Using 'Set' or 'Start'
This problem occurs when we become complacent after using dozens of
PowerShell 'Get' cmdlets. Suddenly it throws an error when you use a
cmdlet starting with: Start, Stop or even Get.
Start-Service : Service 'Print Spooler (spooler)' cannot be started due
to the following error: Cannot open spooler service on computer '.'.
Normally I praise PowerShell's error message, but in this case an extra
message saying, 'You need administrative privileges', would have saved me
angst. Once I understood the problem, the solution was simple,
right-click the PowerShell ISE program and select, 'Run as administrator'.
Guy
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Let us persuade Set-Service to start, or to stop a Windows service.
Incidentally, I like to check the results by launching the Windows Services GUI, I also
make frequent use of F5 to refresh the display after running a PowerShell
command.
# Introduce a variable to highlight the service's name
$CompSrv
="Spooler"
Set-Service $CompSrv -Status "Running"
Other values for -Status are "Paused" or "Stopped". However, I
find that dependencies often get in the way of this method, this is why
I prefer the sister commands, stop-Service or start-Service. What
I like about this pair is that they support the -force parameter.
The syntax is straightforward, stop-Service Spooler -force.
Restart a Windows Service
Clear-Host
$SrvName = "Spooler"
Restart-Service $SrvName
$ServiceAfter = get-service $SrvName
"$SrvName is now " +
$ServiceAfter.status
Learning Points
Note 3: You can create and initialize a PowerShell
simply by using the dollar sign, for example $SrvName =.
Note 4: Observe how we can display properties with the
dot command, for example .status.
Note 5: PowerShell's (+) sign is versatile, not only is it a
math operator, but as here, can also concatenate text.
Note 6: Clear-Host is an unnecessary indulgence, it just
removes traces of all my other failed experiments, which could confuse the
output. See more on
Restart-Service
Error Message With These Scripts
Start-Service : Service 'Print Spooler (spooler)' cannot be started due
to the following error: Cannot open spooler service on computer '.'.
Normally I praise PowerShell's error message, but in this case an extra
message saying 'You need administrative privileges' would have saved me
angst. Once I understood the problem, the solution was simple,
right-click the PowerShell ISE program and select, 'Run as administrator'.
Summary of PowerShell Set-Service
This ezine covers diverse aspects of Windows services. Firstly, the
'Get' verb lists those services installed and displays their status. Secondly,
you can manipulate a named service with 'Set'. Thirdly, remember there
are 3 more verbs for specific tasks, namely, Stop, Start and Restart.
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Tools4Ever
If you like this page then please share it with your friends
See more PowerShell examples of process and service
• PowerShell Home •
Get-Process
• Stop-Process •
Get-WmiObject win32_service
•
Get-Service •
Start-Service •
Stop-Service •
Restart-Service •
Set-Service
• PowerShell Start-Sleep •
Windows
PowerShell
Please email me if you have a better example script. Also please report any factual mistakes, grammatical errors or broken links, I will be happy to correct the fault.
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