Your old screens are named logo.sys, logow.sys and logos.sys [start-up, wait and shutdown.]
Logo.sys is normally located at C:\logo.sys. To save it, rename it logobackup.sys.
Logow.sys and logos.sys are normally located at C:\Windows\logow.sys and C:\Windows\logos.sys. To save them, rename them logowbackup.sys and logosbackup.sys.
Now that you've backed up your original start-up, wait and shutdown screens, open the zip file you just downloaded and extract logo.sys to C:\ and extract logow.sys and logos.sys to C:\Windows and you'll be set :-)
If you have any requests for classic film/celebrity start-up, wait and shutdown screens, e-mail me @ .