Can the XP 'Computer Locked' dialog box be customized?

Solution 1:

Yes, with a custom msgina.dll it should be possible. Have a look at this article about hiding the computer locked dialog which has a replacement msgina.dll.

A warning though before experimenting: msgina.dll is a core system dll which handles the logon process. If you replace it with something that doesn't work you might end up with a computer that is impossible to log on to.

Solution 2:

Its not very difficult:

I know that WindowBlinds can do this but this was so long ago so I forgot how to do it.

Stardock windowblinds

There is also tuneUp utilities that can do it in a more conservative way.

TuneUp