boot screen til xp

Backup (copy) the file %windir%\system32\ntoskrnl.exe (most likely C:\windows\system32\ntoskrnl.exe - the boot screen)
Download the .zip to your computer
Extract ntoskrnl.exe to a directory other than %windir%\system32 (most likely C:\windows\system32)
Reboot your computer into Safe Mode (hit F8 before the boot screen) or into true DOS (from a boot disk)
Overwrite the file %windir%\system32\ntoskrnl.exe (which should have been backed up) with the extracted exe
Reboot your computer as you normally would