Windows

Problem

You want to determine whether a specific hotfix is installed on a system.

Solution

To retrieve a list of hotfixes applied to the system, use the Win32_ QuickfixEngineering WMI class: PS >GetWmiObject Win32_QuickfixEngineering Filter "HotFixID='KB925228'"

Description : Windows PowerShell(TM) 1.0 FixComments : HotFixID : KB925228 Install Date : InstalledBy : InstalledOn : Name : ServicePackInEffect : SP3 Status :

To determine whether a specific fix is applied, use the TestHotfixInstallation script provided in Example 245:

Problem

You want to clear pending print jobs from a printer.

Solution

To manage printers attached to the system, use the Win32_Printer WMI class. By default, the WMI class lists all printers:

PS >GetWmiObject Win32_Printer | SelectObject Name,PrinterStatus

Name PrinterStatus

Microsoft Office Document Image Wr... 3 Microsoft Office Document Image Wr... 3 CutePDF Writer 3 Brother DCP1000 3

Problem

You want to get information about print queues for printers on the current system.

Solution

To retrieve information about printers attached to the system, use the Win32_ PerfFormattedData_Spooler_PrintQueue WMI class:

PS >GetWmiObject Win32_PerfFormattedData_Spooler_PrintQueue | >> Select Name,TotalJobsPrinted >>

Name TotalJobsPrinted

Microsoft Office Document Image Wr...

0 Microsoft Office Document Image Wr...

0 CutePDF Writer

0 Brother DCP1000

2 _Total

2

Problem

You want to get information about printers on the current system.

Solution

To retrieve information about printers attached to the system, use the Win32_Printer WMI class:

PS >GetWmiObject Win32_Printer | SelectObject Name,PrinterStatus

Name
PrinterStatus

Microsoft Office Document Image Wr...
3

Microsoft Office Document Image Wr...
3

CutePDF Writer
3

Brother DCP1000
3

To retrieve information about a specific printer, apply a filter based on its name:

Problem

You want to schedule a task on a computer.

Solution

To manage scheduled tasks, use the schtasks.exe application. To view the list of scheduled tasks:

PS >schtasks

TaskName Next Run Time Status ==================================== ======================== ============= Defrag C 03:00:00, 5/21/2007 User_Feed_Synchronization{CA4D6D9C 18:34:00, 5/20/2007 User_Feed_Synchronization{CA4D6D9C 18:34:00, 5/20/2007

To schedule a task to defragment C: every day at 3:00 a.m.:

Problem

You want to uninstall a specific software application.

Solution

To uninstall an application, use the GetInstalledSoftware script to retrieve the command that uninstalls the software. Since the UninstallString uses batch file syntax, use cmd.exe to launch the uninstaller:

PS > $software = GetInstalledSoftware UnwantedProgram PS > cmd /c $software.UninstallString

Alternatively, use the Win32_Product WMI class for an unattended installation:

The best place to find information about currently installed software is actually from the place that stores information about how to uninstall it: the HKLM:\SOFTWARE\ Microsoft\Windows\CurrentVersion\Uninstall registry key.

Each child of that registry key represents a piece of software you can uninstall—traditionally through the Add/Remove Programs entry in the Control Panel. In addition to the DisplayName of the application, other useful properties usually exist (depending on the application). Examples include Publisher, UninstallString, and HelpLink.

Problem

You want to open or close ports in the Windows Firewall.

Solution

To open or close ports in the Windows Firewall, use the LocalPolicy. CurrentProfile.GloballyOpenPorts collection of the HNetCfg.FwMgr COM object.

To add a port, create a HNetCfg.FWOpenPort COM object to represent the port, and then add it to the GloballyOpenPorts collection:

$PROTOCOL_TCP = 6

$firewall = NewObject com HNetCfg.FwMgr

$port = NewObject com HNetCfg.FWOpenPort

$port.Name = "Webserver at 8080"

$port.Port = 8080

Problem

You want to enable or disable the Windows Firewall.

Solution

To manage the Windows Firewall, use the LocalPolicy.CurrentProfile. FirewallEnabled property of the HNetCfg.FwMgr COM object:

PS >$firewall = NewObject com HNetCfg.FwMgr PS >$firewall.LocalPolicy.CurrentProfile.FirewallEnabled = $true PS >$firewall.LocalPolicy.CurrentProfile.FirewallEnabled True

Discussion

The Group Policy system in Windows stores startup and shutdown scripts under the registry keys HKLM:\SOFTWARE\Policies\Microsoft\Windows\System\Scripts\Startup and HKLM:\SOFTWARE\Policies\Microsoft\Windows\System\Scripts\Shutdown. Each key has a subkey for each group policy object that applies. Each of those child keys has another level of keys that correspond to individual scripts that apply to the machine.

Example 242 allows you to easily retrieve and access the startup and shutdown scripts for a machine.