SOLVED: What happens to WINRM when certs die
Oh boy, this has been a rollercoaster of emotions. Â But guys...we made it. Â We have finally, and definitively answered what happens to WinRM with HTTPs when certificates expire. Â If you're curious about why this is a big question, see my previous posts on this topic. Continue Reading...
Adding tab-completion to your PowerShell Functions
Probably my single favorite feature of PowerShell isn't exciting to most people...but I love Auto-Completion. Â I have my reasons: As I have the typing skills of a preying mantis (why did I mention them...they're easily the creepiest and worst insect...ewww) and constantly typo everything, I LOVE auto-completion. Continue Reading...
Tool-highlight: Show Windows Toast Messages with PowerShell
This will be a quick post here, but I just wanted to shine a spotlight on an AWESOME tool that I absolutely love: Joshua King's 'BurntToast' PowerShell module, which makes the arduous task of rendering a Windows Toast notification VERY Easy. Continue Reading...
Registering for WMI Events in PowerShell
An alternate title might be ‘Running PowerShell Code ONLY when the power state changes’, because that was the very interesting task I received from my customer this week.
It was honestly too cool of a StackOverflow answer NOT to share, so here it goes, you can vote for it here if you thought it was worth-while.
If you want your code to trigger only when the System Power State changes, as described here, use this code.
Register-WMIEvent -query "Select \* From Win32\_PowerManagementEvent" \` -sourceIdentifier "Power" \` -action { #YourCodeHere }
Now, this will trigger whenever the power state changes, whether you plug the device in, OR unplug it. So you might further want to stop and pause to ask the question:
Am I on power or not?
Fortunately we can use the WMI Class Win32_BatteryStatus to detect if we’re charging or not, so here’s the full construct that I use to ONLY run an operation when a power event changes, and then only if I’m no longer on Power.
Locking the workstation when the system is unplugged
Register-WMIEvent -query "Select * From Win32_PowerManagementEvent" `
-sourceIdentifier "Power" `
-action {
if ([BOOL](Get-WmiObject -Class BatteryStatus -Namespace root\wmi).PowerOnLine ){
#Device is plugged in now, do this action
write-host "Power on!"
}
else{
#Device is NOT plugged in now, do this action
write-host "Now on battery, locking..."
[NativeMethods]::LockWorkStation()
}
If you’re curious how this looks in real time
Using PowerShell to register for a WMI event, to lock a workstation on power state change pic.twitter.com/JtJWDosA4b
— Stephen Owen 🦊Deploy (@FoxDeploy) December 15, 2016
Registering for device events
It can also be useful to have your code wait for something to happen with devices, such as running an action when a device is added or removed. To do this, use this code.
#Register for power state change
#Where TargetInstance ISA 'Win32_Process'"
Register-WMIEvent -query "Select * From Win32_DeviceChangeEvent where EventType = '2'" `
-sourceIdentifier "Power" `
-action {#Do Something when a device is added
Write-host "Device added at $(Get-date)"
}
You might also want to do an action if a device is removed instead, so use this table to choose which event is right for you. Read more about it here.
| EventType | Id |
|---|---|
| ConfigurationChanged | 1 |
| Device Arrived | 2 |
| Device Removed | 3 |
| Device Docked | 4 |
What else can I wait for?
Not only these, but you can trigger your code to execute on a variety of useful WMI Events, all of which can be seen in this image below!
| ClassName | Triggers when |
| Win32_DeviceChangeEvent | A device is installed, removed, or deleted, or the system is docked |
| Win32_VolumeChangeEvent | Something happens to your disk drives |
| Win32_PowerManagementEvent | Your device is plugged, unplugged or docked |
| Win32_ComputerSystemEvent | Something major happens to the system |
| Win32_ComputerShutdownEvent | The system is shutting down! |
| RegistryEvent | Anythign happens to the registry |
| RegistryKeyChangeEvent | A reg key you specify is changed |
| RegistryValueChangeEvent | A reg value you specify is changed |
Locking your Workstation with PowerShell
Locking a workstation using PowerShell? Â It sounds like an easy task, right? Â That's what I thought too...and told the customer...but NO! Â Friends, it wasn't easy...before now. As it turns out, some tasks in Windows just aren't accessible via WMI. Â For instance, the useful Win32Â OperatingSystem class has some nifty methods for working with the system's power state, like Reboot and Continue Reading...
Hands-off deployments
Let's face it, guys. Â There are times that you JUST don't have access to SCCM, MDT or Kace, and need to deploy a completely automated and silent Windows install without our normal build tools. Â If this is you, and you deploy systems frequently, you've probably spent way too much time looking at screens like this one Continue Reading...
