OK, for starters, please only post your question once - multiple postings won't necessarily get your problem solved any quicker.
Secondly, calm down and tell us exactly what your problem is in plain English.
Are you saying that you can't install DirectX 9.0c in Windows XP SP2? If I remember right, SP2 already includes 9.0c, why would you want to install it again? If your games are complaining about not having 9.0c installed, I would uninstall SP2 and reinstall it. If you're having problems with "The Cabinet cannot be trused" messages, take a look
here for a solution.
What makes you think you have DirectX 5 installed? As far as I'm aware, Windows XP comes with DirectX 8 as the base version - so there's no way you could have DirectX 5 installed. What it could mean is that you have some very old drivers installed - you may want to make sure that your video card, sound card drivers etc. are upgraded to the latest versions.