.logonxp is a renamed .zip that LogonStudio understands
try renaming to .zip, extracting out the folder and moving the folder to where the others are
did you install LogonStudio to it's default path or other?
LogonStudio for XP is free, unlimited and can be used to create your own.
did you download/install LogonStudio or is the one you have one that came with AlienGuise?