32bit printer driver on 64bit system - migration from Windows 2008 to Windows 2012R2

If you want to add 32 bit drivers to 64 bit Print Server You must use pnputil to upload drivers to the system (like for 64 bit drivers) and finally You must use 32bit Powershell Add-PrinterDriver – from this level enabling 32bit drivers is possible on 64bit system.

How to start 32bit version of Powershell? MSDN link:
Starting the 32-Bit Version of Windows PowerShell

When you install Windows PowerShell on a 64-bit computer, Windows PowerShell (x86), a 32-bit version of Windows PowerShell is installed in addition to the 64-bit version. When you run Windows PowerShell, the 64-bit version runs by default.

However, you might occasionally need to run Windows PowerShell (x86), such as when you are using a module that requires the 32-bit version or when you are connecting remotely to a 32-bit computer.

To start a 32-bit version of Windows PowerShell, use any of the following procedures.
In Windows Server® 2012 R2

On the Start screen, type Windows PowerShell (x86). Click the Windows PowerShell x86 tile.
In Server Manager, from the Tools menu, select Windows PowerShell (x86).
On the desktop, move the cursor to the upper right corner, click Search, type PowerShell x86 and then click Windows PowerShell (x86).
Via command line, enter: %SystemRoot%\SysWOW64\WindowsPowerShell\v1.0\powershell.exe

In Windows Server® 2012

On the Start screen, type PowerShell and then click Windows PowerShell (x86).
In Server Manager, from the Tools menu, select Windows PowerShell (x86).
On the desktop, move the cursor to the upper right corner, click Search, type PowerShell and then click Windows PowerShell (x86).
Via command line, enter: %SystemRoot%\SysWOW64\WindowsPowerShell\v1.0\powershell.exe

In Windows® 8.1

On the Start screen, type Windows PowerShell (x86). Click the Windows PowerShell x86 tile.
If you are running Remote Server Administration Tools for Windows 8.1, you can also open Windows PowerShell x86 from the Server ManagerTools menu. Select Windows PowerShell (x86).
On the desktop, move the cursor to the upper right corner, click Search, type PowerShell x86 and then click Windows PowerShell (x86).
Via command line, enter: %SystemRoot%\SysWOW64\WindowsPowerShell\v1.0\powershell.exe

In Windows® 8

On the Start screen, move the cursor to the upper right corner, click Settings, click Tiles, and then move the Show Administrative Tools slider to Yes. Then, type PowerShell and click Windows PowerShell (x86).
If you are running Remote Server Administration Tools for Windows 8, you can also open Windows PowerShell x86 from the Server ManagerTools menu. Select Windows PowerShell (x86).
On the Start screen or the desktop, type PowerShell (x86) and then click Windows PowerShell (x86).
Via command line, enter: %SystemRoot%\SysWOW64\WindowsPowerShell\v1.0\powershell.exe

I testted this procedure with about 300 drivers (150 64bit and 150 32bit) and it works perfectly. It was a migration from 2008R2 Print Server to 2012R2 PrintServer.

Available tools (Print Migration Wizzard) can't manage huge print drivers library (above 2GB), we had 4,5GB so only manual process was possible. We migrated manually all drivers (copy all *inf* folders with printer drivers), register them using pnputil, add ports using PowerShell, add printers (connect them 64bit drivers with Ports) and later using 32bit version of Powershell:

- add printer drivers for 32bit.