How do you repair with the Windows CD?

[veronica]

I was going to follow the Langa Letter, http://www.informationweek.com/hardware/personaltech/189500364 but my CD is SP1. The OS on my PC is SP2. Will it still work?

Is this the right way to repair my OS with the Windows CD?

I already tried the sfc /scannow thingy.

Thanks