MDT Computer Naming

[rsadmin86]

I have a SCCM 2012 R2 SP1 environment running MDT 2013. I have created a MDT Task sequence and configured it with he UDI interface. I have everything setup except for the automatic computer naming. When I created a non-MDT task sequence I used this script:

 

#get serial number

$SerialNumber = (Get-WmiObject -Class Win32_BIOS | Select-Object SerialNumber).SerialNumber

#get count of characters in serial

$count = $SerialNumber.length

#find number of characters that need to be removed

$Trim = ($count -6)

#remove characters to get last 6 characters in serial

$last6 = $serialnumber.substring($Trim)

#combine "lt" and last 6 characters of serial

$Computername = "lt" + $last6

$TSEnv = New-Object -COMObject Microsoft.SMS.TSEnvironment

$TSEnv.Value("OSDComputerName") = "$ComputerName"

 

 

But now that I have an MDT Task sequence and since I am using the UDI wizard to configure the interface, I am not sure where to put this the script. My goal is to have the MDT task sequence determine the hardware (Laptop or Desktop) add a prefix (DT, or LT). I thought I could do this through a script where I added a custom Task sequence variable called OSDComputerNamePrefix. When I run the Task sequence it Prompts for a Prefix, and the user will enter it in manually i.e. "LT", then I was hoping to be able to run this script:

 

$SERIAL = (Get-WmiObject win32_bios).serialnumber

 

New-Object string (,@($serial.ToCharArray() | Select-Object -Last 6))

$TSEnv = New-Object -COMObject Microsoft.SMS.TSEnvironment

$TSEnv.Value("OSDComputerNamePrefix") = "$Prefix"

#combine "Prefix" and last 6 characters of serial

$Computername = $Prefix + $SERIAL

$TSEnv = New-Object -COMObject Microsoft.SMS.TSEnvironment

$TSEnv.Value("OSDComputerName") = "$ComputerName"

I was hoping this would name the computer, however the task sequence fails with a 0x8000405 error. I have the script running right after the Format and Partition Disk in my task sequence. I attached a picture of my task sequence. I think I am getting confused on which components to change because there are so many (UDI wizard, MDT Task Sequence, CustomSettings.ini).I tried to use the same customSettings.ini file that was used here: http://www.ronnipedersen.com/2014/10/setting-osdcomputername-using-customsettings-ini/ and http://c-nergy.be/blog/?p=3933 and http://deploymentbunny.com/2012/04/21/back-to-basic-customsettings-ini-explained/

but when my UDI starts all I get is LT%ComputerSerialNumber% or LT#Left("SerialNumber%",6)#.

Not sure why that is failing to gather the last 6 of the serial number. The naming conventions should be Prefix (LT, or DT) with the last sixof the computer serial number. Example LT1231dh.

Thank you for your help.