Win XP Logon Screens

I want to put a different XP Logon screen on, but Im not sure about them.
Just a few questions:

What happens if you install one and it doesnt load on your computer? Does that mean I wont be able to log on therefore Im nackered?

How do I change back if I dont like the one I download?

Should I risk it, or just stick with my default one and be better safe than sorry?

If anyone has any logon screens can they recommend any sites with them on so I know they'll work.

Thanx in advance.
Geordie

 

The boot screen is a resource of ntoskrnl.exe, a system file. Some people have indeed reported being unable to boot after replacing it (which must be done in Safe Mode since it is a protected file, and the old one will be replaced if you run a system file check).

Hacking this file to replace the bitmap portion is dangerous. Some copies of ntoskrnl.exe circulating in file-sharing networks are infected with viruses.

If you attempt to do this, be sure to make a backup or restore point prior to the attempt.

It would be safest to use a commercial product:
www.bootxp.net

Some of the commercial products do not work with SP1.

PS. On rereading, I realized you were talking logonui and not boot screens. Most of what I said still applies. Look here:
http://users.resentment.org/windowsxp/logon.htm
http://www.belchfire.net/modules.php?name=XP_Themes

 

Thnik I'll give it a miss after reading what you said, Id rather play it safe.

Thanx alot.