OK:
logon screen: [spoiler]in System32 is file LOGONUI.EXE - original logon screen
Create new file - for example LOGONNEW.exe in System32.
edit registry address: Hkey_Local_Machine\Software\Microsoft\Windows NT\CurrentVersion\Winlogon
in UIHost entry, change the value LogonUI.EXE for LOGONNEW.EXE. [/spoiler]
Boot screen: [spoiler] System32 -> NTOSKRNL.EXE - original boot screen.
Create new file - f.e: NTOSOBR.EXE in System32
Edit boot.ini file.
copy line under [opreating systems] (it looks like this: multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional" /noexecute=optin /fastdetect) and paste it under the original line, and write this in the end: /KERNEL=NTOSOBR.EXE
It should look like this:
[boot loader]
timeout=30
default=multi(0)disk(0)rdisk(0)partition(1)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional" /noexecute=optin /fastdetect
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional" /noexecute=optin /fastdetect /KERNEL=NTOSOBR.EXE
Now after reboot you'll have 2 OS to run(one is oroginal, the second is with new bootscreen.)
If the new boot runs good, you can dlete the original line. else start with normal boot screen and delete the line added.
[/spoiler]
Or try this
I also found that TuneUp allows you to do this.
