Yup, done that a few dozen times in the last 3 weeks.
Bios, set controller to RAID, save, reboot and hit Ctrl+I, setup RAID, save and reboot with W7 CD in drive, W7 starts to install on reboot, and after selecting the language option it goes to "Where's the freakin drivers you idiot" gimmie my drivers!!!
If I go thru the install W7 routine with just 1 hard drive in AHCI mode (no RAID) it cruises right on thru and installs completely, installs other programs (Office, Adobe etc).
I've updated the BIOS to F3, downloaded ALL motherboard drivers from the Gigabyte website.