If you are using the pSeries PCMCIA card containing the 1410 or 1420 chipsets, it will be possible for you to use the latest Window 32-bit Vista in your system. However, it will not be possible for you to use them if you are using the legacy models. You may also remember that pSeries can be supported in Vista only if you have 32-bit systems. You can not use it with 64-bit platforms.
Of course the latest of the pSeries drives will install in Windows vista but may require some small modifications. Else it may show the error message for you. It will not run in the previous versions of the pseries which means you may not be able to deploy the used pseries. Therefore it is almost mandatory for you to install the latest pseries driver so that your equipments work perfectly in the Windows Vista environment.
You can go through the step by step guide that is provided for the purpose by your provider. As a first step you can save the driver required for the installation in your desktop. You may start by double clicking the installation. You may continue with the installation despite getting some warning message regarding the pseries exe trying to access your computer. Once the process of installation is performed, you can work with the Windows Vista using the pseries installations.