If you tried breaking the array, you would lose all of your data on both drives, so have it backed up first. Then, you can go into the BIOS/controller and turn off RAID, making them just individual drives...probably by setting your controller to AHCI, or IDE if not available. Once this is done, you can follow our guide here in Tutorials for a clean install, using DISKPART to clean the drives and install Windows 7.
If it was me, I'd consider selling one or both Raptors, and putting that money towards an larger storage drive, or an SSD. RAID0 was great in theory and hype, but never really yielded actual boosts in normal usage, so you won't be missing out by soing away with it.