Adding Stipped Volume to existing setup?

Hi, I have Vista 64 Ultimate installed on my 150gig Raptor.
I just connected 2 more Raptors(75gig each) and I want to create a raid 0
out of them and add it to the system.

I don't want to boot from the raid 0, because the OS is already on another HD.

Is there a way to do this easily? I saw the "Add New Stripped Volume"
option in Disk Management, but I'm afraid if I go through with it, that it
will wipe my original Vista Install.

Could anyone help out?

Thanks!