>Does anyone know what operating systems the Scripting.FileSystemObject
>is available in?
>

It's avaialble in any environment that you can install the WSH in - essentially any Win32 platform except Win32S, or NT before SP3 - if you can install IE4 or later, you can install the WSH from the self-extracting executable.

Unless you do something to install it, it is not present, except of Win98 and Win2K which incorporate the IE4 or IE5 browser in their base installs.