⟩ Can Exchange 5.5 or Exchange 2000 run on Windows 2003?
NO. Windows 2003 uses IIS 6.0, which has been re-engineered to keep up with best practices and industry standards. Windows 2003 has an IIS 5.0 compatibility mode, however, it is not compatible with Exchange 5.5 or Exchange 2000. Therefore, neither Exchange Systems are compatible with Windows 2003.