PROBLEM:

Unable to boot into XP in any mode (Safe Mode, Safe Mode with Networking, Normal Windows, etc.). When using the XP Setup CD and going into the  into the Recovery Console, you are prompted me for my Administrative Password. But you don't know the password...

SOLUTION:

1/ Download a DOS recovery tool that includes a registry editor (I use Avast BART CD).

2/ Boot into the recovery tool and edit the registry:

Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WindowsNT\CurrentVersion\Setup\RecoveryConsole
Set the DWORD SecurityLevel value to 1

3/Exit Registry and Reboot

You are now allowed to access the recovery console without inputting a password.