I recently upgraded my operating system from Win 98 to XP Pro. I therefore needed to reinstall MSFS 2004 and obtain another FSUIPC to work with my ELITE PI 121 PCATD. Iwent to simarket and obtained a key for a registed version. I originally downloaded 3.52 to my desktop and then moved the contents to the modules folder. I then registed using the key provided by simmarket. It did not work with my hardware. I then went to your forums page and went back to download 3.53. It works just as well, (not at all). If I am overlooking something in the installation process please direct to me to some detailed instructions. 3.53 does currently show as a registered version but still does nothing with my hardware. I did not have this problem when installing the FSUIPC previously on both MSFS 2002 and 2004 while running Win 98. Your assistance would be greatly appreciated. I am not primarily a software engineer, just a pilot.