The Bomb Factory Plug-ins included with the Digi 001 Factory bundle need to be updated to version 3.0.2 in order to use them with Pro Tools LE 5.3.1 for Windows XP.From the Pro Tools LE 5.3.1 for Windows XP Updates page in the Support/Downloads section of the Digidesign website: www.digidesign.com update your Digi 001 Factory Bundle software from Bomb Factory for Windows XP compatibility, you will need to download the free update for the 3 Bomb Factory plug-ins included with the Digi 001 Factory:Classic Compressors: 1176Classic Compressors: LA-2Amoogerfooger Lowpass FilterTo Download the free update:1 - Go to bombfactory.com - Click on "downloads"3 - Click on "demos/updates"4 - Fill out the form to create an account, and Bomb Factory will email you instructions to access downloads.5 - Once there, download the following: 001 Factory Free Windows XP UpdateThese updates require the preauthorized iLok included with your Digi 001 Factory purchase.