install windows 7 64 bit on a computer with a scsi drive

Hi im woundering if anyone knows how to get windows 7 64 bit onto a dell precision 380 it, when it was new it came with windows xp and now i have windows 7 64 bit the pc but i need to reinstall windows 7 64 bit back onto it and i can see to get the install to see the scsi drives what can i do?