The way I accomplished the task is as under:
Copied the .gif file to the location /_layouts/images in which I found the sitelogo.gif file (SharePoint's default logo file)
Went into IIS Manager, selected Web Sites, CompanySite (I did not use the default web site, but I guess that does not matter) -> _layouts -> images and I found the gif file that I had inserted
Is this the correct approach, can you add a gif file directly in IIS Manager in the _layouts/images folder ???