Shutdown Screen ?

HI.
I changed the bitmap image for the “Windows shutting down image, and the “Its now safe to turn your computer off” image. The files are in the windows directory called “Logow.sys” and “Logos.sys” respectively.
I put new images in that directoryand named them accordingly, only to get nothing. I tried a number of different things, all to no avail. Now I changed the backed-up files to the original names, and still get nothing. What do you think.
One other thing…I cant find the startup image called Windows 98. The file is called “Logo.sys”. I still see it everytime I boot up, but its not there in the windows directory.