$computerlist = Get-Content .\computer_list.txt
$computername = @{name='ComputerName';expression={$_.__SERVER}}
$BIOSSerialNumber = @{name='BIOSSerialNumber';expression={Get-WmiObject -class Win32_BIOS -computername $computerlist |
Select-Object -ExpandProperty SerialNumber}}
$ServicePack = @{name='Service Pack';expression={$_.csdversion}}
$OperatingSystem = @{name='Operating System';expression={$_.caption}}

Get-WmiObject -class Win32_OperatingSystem -ComputerName $computerlist |
select -property $computername,$OperatingSystem,$ServicePack,$BIOSSerialNumber


(This is what I get)
ComputerName   Operating System         Service Pack                     BIOSSerialNumber
 ------------ ---------------- ------------        ----------------
001 Microsoft Windows 7 Enterprise       Service Pack 1                 {?????H1, ?????D1}
 017 Microsoft® Windows Vista™ Enterprise Service Pack 2     {?????H1, ?????D1}

(This is what I am expecting)
ComputerName Operating System                   Service Pack                  BIOSSerialNumber
------------ ---------------- ------------                      ----------------
001 Microsoft Windows 7 Enterprise                  Service Pack 1                 ?????H1
017 Microsoft® Windows Vista™ Enterprise     Service Pack 2               ?????D1

I am making a hardware inventory script, but encountered a small issue.

Information is being pulled from each machine ,listed per line in computer_list.txt, but the serial numbers are listed together and on one line.

What am I overlooking; is it something with nested objects?

The same results are displayed when using the foreach-object enumerating method. The correct OS is displayed for each machine listed, so that tells me (Get-WmiObject -class Win32_OperatingSystem) is receiving a string from each line of the $computerlist variable. I am guessing the $BIOSSerialNumber variable's -computername parameter is causing the issue.

This code...

$BIOSSerialNumber = @{name='BIOSSerialNumber';expression={Get-WmiObject -class Win32_BIOS -computername $computerlist | Select-Object -ExpandProperty SerialNumber}}

... collects all the Bios Serial Numbers from all of the computers in $computerlist and puts them into one array... thats why you get {?????H1,?????D1} etc

The code doesn't try and match the BIOS data with the Operating System data

I would re-structure the code like this...



Does that make sense?

If I am understanding this correctly, you created a custom object combined with a hashtable, correct?

Not really, I created a custom object with "properties defined by a hash table".

$CombinedData=@() defines an empty array. We create new-objects with properties and values we define, and add it to this array.

$CombinedData+= adds the new object we create to the array

Sometimes people use a temporary variable within the loop to create the new-object.

$temp=New-Object PSObject -Property @{.....}

Once the new object is created, then it's added it to the array.

$CombinedData+=$temp

I've decided not use a temporary variable, logically there's no reason for it.

$CombinedData+=New-Object PSObject -Property @{.....}

$CombinedData by itself at the end just displays what's in the array after we've finished adding our objects.

Any clearer?