A. One of the great features of Vista WIM technology is that, theoretically, updates can be slipstreamed into an image file. So, when service packs are released, you don't have to recapture images. Unfortunately, this isn't the case with Vista SP1 because it updates the servicing stack, which is responsible for servicing a Windows image.
To update the WIM files, you need to install the WIM file on a computer, then install SP1. Next, run SYSPREP on the machine and recapture the image to a new WIM file. Normally, running this SYSPREP would decrement the Vista installation re-arm count. However, because the SP1 installation requires an image recapture, Microsoft included an extra re-arm.
Make sure you use the latest Windows Automated Installation Kit (WAIK) version at Automated Installation Kit (AIK) for Windows Vista SP1 and Windows Server 2008 . It supports Windows Server 2008 and Vista SP1.