Save select programs before a reformat?

Hi all,

Heres the dilemma i have:

I bought a game but cant install it because it requires DirectX 8 or above. I have XP SP2 which comes with v9.0c (if i remember rightly) but when i open DXDIAG it says that my current version is 0.0.

Now i have been trying to find a solution to get directX on my computer for a week or so, i have tried everything bar a reformat. I have now resigned myself to the fact that the only way i can play the game is to reformat and let windows install everything anew.

But i have a few questions:
1. I cant locate my original windows XP setup CD. Is this needed for a reformat?
2. Is it possible to save select software so that i cant easily transfer them back after a reformat?

The reason for number 2 is because i have probably spent over £2K on software in the last 4/5 years; buying programs online and then being emailed a registration key etc... the problem is that i probably only have the CD's/reg keys for about 10% of them in the event i had to install them again. Others are long gone into oblivion with dead emails and deleted files. So is there a way i can transfer select programs over? I dont want to transfer all over, there are some i can live without/dont use anymore.

Thanks for your time.