bro,PLEASE do the following
1| set SATA in bios to AHCI or RAID, keeping ODD as the primary boot option
3| format OS drive during reinstall of windows 7
4| this should solve the problem of your keyboard.
BTW, is keyboard, usb or PS2? usually a bios update can solve these lil issues as the updated vers account for ps2 glitch, ram or cpu support