drive not showing in Windows setup

drive not showing in Windows setup

I accidentally formatted my OEM drive of M DELL Inspiron. After that I could not install Windows 7 on my laptop. Because the partitions of my hard disk are not showing to select an install drive. I downloaded the RAID driver from the Dell Support website for my laptop, but the driver is showing and I loaded the driver from a pen drive. But it's still not showing the drives.