Automatic File Compression

[Al]

Myself and one of my clients are having a problem with
automatic file compression. It seems on XP Pro that some
files are being compressed without our requesting or
doing it ourselves. The files are of all types,
including data files. They file name appears blue, and
when you right mouse click and go to properties, and then
the advance button, it tells you it is compressed. I
have searched everywhere for this setting to see if I can
turn it off. The commercial client is having important
data files compressed which is causing performace and
other issues across the network. Any help you could give
me would be greatly appreciated.