More usefull powershell commands

Alternate authentication cmdlet
Sometimes it is pretty useful to be able and use alternate credentials in PowerShell command. This can be done by using Get-Credential cmdlet but a downside is that you can not specify password. Instead what will happen every time this cmdlet is ran it will produce a popup box to enter password.
A nice workaround is to store the credentials in encrypted variable such as $cred = Get-Credential Administrator this will initially pop up with authentication box where password is typed in but afterwards you can use $cred variable in your session without need to type it in again.

Run PowerShell command in background and keep control of your session for other tasks
In the situation where we need to run a cmdlet where output will take a while to be produced we can use -asjob switch. This will give us back our prompt to run additional command while our initial query will run in the background. Some of the related cmdlets with which we can control or view jobs are: Get-Job, Receive-Job, Remove-Job, Resume-Job, Start-Job, Stop-Job, Suspend-Job, Wait-Job

Output text in PowerShell
Write-Output

Input some text into powershell
Read-Host

Convert output of query to HTML
This is specifically usefully if desired output needs to be shared for wide audience. All needs to be done is convert it to HTML using ConvertTo-hmtl and output to file using Out-File to write contents into file on web server and your info is readily available for brain consumption.

Import contents of file into PowerShell for processing
Best example for this would be creating multiple users in AD from predefined csv file. We can use Import-CSV cmdlet to take a contents of csv file and pipe it into another cmdlet such as Import-CSV file.csv | New-ADUser. Please note that header of csv file should contain valid AD properties for user. Whichever properties you have, those properties will be created along with a user.

Basic help powershell commands that make life easier

get-help
displays help for desired commandlet

get-help -full
displays full help for desired commandlet including examples

get-help -online
if you have internet access this will display online help for any commandlets desired

update-help
downloads and installs help files from internet

show-command
opens gui for desired commandlet where you can see whole bunch of options and parameters. If desired these parameters can be filled out in gui and copied to run in PowerShell window in order to see exact syntax

get-command
this will list commands that pertain not only to PowerShell but a whole system

get-member
gets the properties and methods of objects. This is very useful to see what custom fields/methods you can use for specific cmdlet

Script to find files in size greater than desired size

Very useful when you need to find large size files on your system. This command can be run locally or on remote system as long as you have admin rights to remote system.

Get-ChildItem \\servername\c$ -Recurse -ErrorAction "SilentlyContinue" | Where-Object {$_.Length -gt 100MB} | Export-Csv c:\temp\myLargeFilesOnC_Report1.csv

Gracefully shutdown VM using PowerCLI

This is very useful for me when I need to power off my lab at home (trying to conserver energy) :)

Prerequisites for this to work is that you have PowerCLI installed on your computer as well as vm tools installed on all vm's that you would like to utilize this on

Power off single machine:

get-vm vm-name | ShutdownVMGuest

Power off group of machines:

Create a text file with list of vm's you would like to shut down with each vm in separate line such as
vm1
vm2
vm3
Let say this file is called servers.txt and is located in c:\users\mike\desktop
First we will create variable to load servers from text files:
$servers = Get-Content -Path c:\users\mike\desktop\servers.txt
second we will use previous command to shut down group of servers in the file:
get-vm $servers | Shutdown-VMGuest

Turn on group of machines: (This please be careful with as if you try to turn on too many machines at one time you could potentially overload your ESX box)

Start-VM -VM $servers

IP address already assigned to another adapter

This issue occurs if a network adapter with the same IP address is in the Windows registry but is hidden in the Device Manager (My Computer > Properties > Hardware > Device Manager). This hidden adapter is called a ghosted network adapter.

• You may see this if you recently performed a P2V and the resulting virtual machine still has the physical NICs and drivers for those NICs present. These ghost NICs have the old IP address and the virtual NIC cannot be assigned the same IP address.

Using the Show hidden devices option in the Device Manager (View > Show hidden devices) does not always show the old virtual NIC (ghosted adapter) to which that IP Address is assigned.

 

To resolve this issue, make the ghosted network adapter visible in the Device Manager and uninstall the ghosted network adapter from the registry:

1. Click Start > Run.
2. Type cmd and press Enter.
3. At the command prompt, run this command:
   Note: In Windows 2008 and Windows 7, open the command prompt using the Run as Administrator option.
   
   set devmgr_show_nonpresent_devices=1
   Note: If this command does not work (a possibility in Windows Server 2000 and 2003), you may need to add the parameter to Windows and set its value:
   
   
   1. Right-click the My Computer desktop icon and choose Properties.
   2. Click the Advanced tab and select Environment Variables.
   3. In the System variables section, click New.
   4. Set the Variable name to devmgr_show_nonpresent_devices and set the Variable value to 1 to enable the parameter.
   5. Click OK to add the variable to Windows.
      
4. Start the Device Manager by running this command from the same command prompt:
   
   start devmgmt.msc
   
5. Click View > Show Hidden Devices.
6. Expand the Network Adapters tree (click the plus sign next to the Network adapters entry).
7. Right-click the dimmed network adapter, then click Uninstall.
8. Once all of the grayed out NICs are uninstalled, assign the IP address to the virtual NIC.
   
   Note: To assign the IP address to the virtual NIC on the command line, run the command:
   
   netsh interface ip set address "Local Area Connection #" static IP_Address Subnet_Mask Default_Gateway
   
   For example:
   
   netsh interface ip set address "Local Area Connection 2" static 192.168.1.101 255.255.255.0 192.168.1.1
   
   
9. Close the Device Manager

Source of this article: VMware KB1179 

How to manually push update if Global Address Book Exchange 2010 Taking time to update new user

1. Get-GlobalAddressList | Update-GlobalAddressList
2. Get-OfflineAddressBook | Update-OfflineAddressBook
3. Get-ClientAccessServer | Update-FileDistributionService
4. Download Full OAB in outlook
5. On the Tools menu, point to Send/Receive, and then click Download Address Book.
6. In the Offline Address Book dialog box, make sure that the Download changes since last Send/Receive check box is checked.
7. Click OK.

Query interface information on remote machines

I found a nice script for this task that can be found by following link:
Scrip Source

The powershell command to run in order to query list of computers from text file list would be as follows:
$computers = Get-Content -Path c:\scripts\servers.txt
.\getipinfo.ps1 -ComputerName $computers | ft -AutoSize


This is the actual script:
[cmdletbinding()]
param (
[parameter(ValueFromPipeline=$true,ValueFromPipelineByPropertyName=$true)]
    [string[]]$ComputerName = $env:computername
)           

begin {}
process {
foreach ($Computer in $ComputerName) {
  if(Test-Connection -ComputerName $Computer -Count 1 -ea 0) {
   $Networks = Get-WmiObject Win32_NetworkAdapterConfiguration -ComputerName $Computer | ? {$_.IPEnabled}
   foreach ($Network in $Networks) {
    $IPAddress  = $Network.IpAddress[0]
    $SubnetMask  = $Network.IPSubnet[0]
    $DefaultGateway = $Network.DefaultIPGateway
    $DNSServers  = $Network.DNSServerSearchOrder
    $IsDHCPEnabled = $false
    If($network.DHCPEnabled) {
     $IsDHCPEnabled = $true
    }
    $MACAddress  = $Network.MACAddress
    $OutputObj  = New-Object -Type PSObject
    $OutputObj | Add-Member -MemberType NoteProperty -Name ComputerName -Value $Computer.ToUpper()
    $OutputObj | Add-Member -MemberType NoteProperty -Name IPAddress -Value $IPAddress
    $OutputObj | Add-Member -MemberType NoteProperty -Name SubnetMask -Value $SubnetMask
    $OutputObj | Add-Member -MemberType NoteProperty -Name Gateway -Value $DefaultGateway
    $OutputObj | Add-Member -MemberType NoteProperty -Name IsDHCPEnabled -Value $IsDHCPEnabled
    $OutputObj | Add-Member -MemberType NoteProperty -Name DNSServers -Value $DNSServers
    $OutputObj | Add-Member -MemberType NoteProperty -Name MACAddress -Value $MACAddress
    $OutputObj
   }
  }
}
}           

end {}