I don't have much experience with Delphi 9 (Delphi 2005 if I'm correct), however I do know that Delphi 2005 can compile Win32, however I have no clue in how far it is compatible with Win98 etc.

I'm actually still using Delphi 6, however I did manage to install Delphi 7 Personal on a Windows 98 machine so I guess Delphi 7 is fully Win32/Win98 compatible... of course there are always some things that will never work without XP or 2000 but they are mostly API related...