You aren't using a RAID are you? And technically SSDs do use drivers; or rather your mobo uses AHCI drivers. Though at least when I last tried using them, AMD's AHCI drivers caused me a lot of problems and the recommended course of action was to just let Windows install it's own. Intel's are solid as far as I recall.
It seems strange that it would ask for it now, though I suppose if you're booting to the disc (I'm guessing here) and the OS itself isn't loading it may not have access to the already installed drivers?