Inventorying Active Directory Computers with Powershell

Get-ADComputer

The cmdlet of choice for inventorying computers through AD is Get-ADComputer. This command automatically searches for computer objects throughout a domain, returning all sorts of info.

Import the ActiveDirectory module:



Then if I want to see all the details about using this cmdlet, I run:

Get-Help Get-ADComputer -Full


As you get comfortable with AD PowerShell, I highly recommend that you start tuning for less data to be returned - the "filter left, format right" model described here by Ned Pyle.

Get-ADComputer -Filter * -Property * | Format-Table Name,OperatingSystem,OperatingSystemServicePack,OperatingSystemVersion -Wrap –Auto



This command is filtering all computers for all their properties. It then feeds the data (using that pipe symbol) into a formatted table. The only attributes that the table contains are the computer name, operating system description, service pack, and OS version. It also automatically sizes and wraps the data. When run, you see:



One Windows Server 2003 computer needs Service Pack 2 installed and there are still Windows 2000 servers running.

Server Filtering

Now break down the results with filters:

Get-ADComputer -Filter {OperatingSystem -Like "Windows Server*"} -Property * | Format-Table Name,OperatingSystem,OperatingSystemServicePack -Wrap -Auto
You can change the filter to find all the computers that are running “Windows Server something”, using the –like filter. 



Now only servers are listed. Where did the Windows 2000 server go? Microsoft didn’t start calling OS’s “Windows Server” until 2003. Before that it was “Windows 2000 Server”. We need to change the filter a bit:

Get-ADComputer -Filter {OperatingSystem -Like "Windows *Server*"} -Property * | Format-Table Name,OperatingSystem,OperatingSystemServicePack -Wrap -Auto
Just added an extra asterisk to Server (*Server*).


 
As you can see, this environment has a variety of Windows server versions running. We are interested only in the ones that are running Windows Server 2008 or Windows Server 2008 R2. Once we get that, I might just want to see the R2 servers – We run these two sets of commands:

Get-ADComputer -Filter {OperatingSystem -Like "Windows Server*2008*"} -Property * | Format-Table Name,OperatingSystem,OperatingSystemServicePack -Wrap -Auto

Get-ADComputer -Filter {OperatingSystem -Like "Windows Server*r2*"} -Property * | Format-Table Name,OperatingSystem,OperatingSystemServicePack -Wrap -Auto


Only R2 Servers:

Workstation Filtering

Simply switch from -Like to -Notlike from my previous server query:

Get-ADComputer -Filter {OperatingSystem -NotLike "*server*"} -Property * | Format-Table Name,OperatingSystem,OperatingSystemServicePack -Wrap -Auto

Family filtering

If you want to filter by the “family” of operating systems. This can be useful when trying to identify computers that started having a special capability in one OS release and all subsequent releases, or we don’t care about it being server or workstation. Example would be BitLocker – it only works on Windows Vista, Windows Server 2008, and later. run:

Get-ADComputer -Filter {OperatingSystemVersion -ge "6"} -Property * | Format-Table Name,OperatingSystem,OperatingSystemVersion -Wrap -Auto
Filtering on operating system version needs to be equal to or greater than 6. This means that computers that have a kernel version of 6 (Vista and 2008) or higher will be returned:



For Windows Server 2008 R2 and Windows 7 family of computers, we change the filter slightly:

Get-ADComputer -Filter {OperatingSystemVersion -ge "6.1"} -Property * | Format-Table Name,OperatingSystem,OperatingSystemVersion -Wrap -Auto

Getting it all into a file

This is where Export-CSV comes in. With the chaining of an additional pipeline I can find all the computers, select the attributes I find valuable for them, then send them into a comma-separated text file.

Get-ADComputer -Filter * -Property * | Select-Object Name,OperatingSystem,OperatingSystemServicePack,OperatingSystemVersion | Export-CSV AllWindows.csv -NoTypeInformation -Encoding UTF8

 
Open AllWindows.CSV file in Excel and: