Could be any number of things. Please list your complete configuration; ie: motherboard, cpu, memory brand and type, hard drives, optical drives, video card, and power supply.
As far as your hard drives... the boot order, or what controllers are "enabled", has a major influence on your drive letter designations and such. Don't connect any extra HDDs till you get your base install done... or you may find you have installed windows on a different HDD then what you had planned!
Have you done all your Windows updates? Are you using the drivers for the NForce3, not 4 (makes a difference... system will get unstable if using wrong RAID/chipset drivers). Make sure ALL your drivers are the latest, the ones on the CD were outdated the day the CD was made. You can find most of the updated drivers
HERE. Have you plugged in BOTH power supply connectors to motherboard. If your vid-card has a power connector, is that hooked up?
This is a new system... have you "burned it in"? Doubtful... Without knowing the stop error for the blue screen... we can't help you.
Have you checked for an updated BIOS for your motherboard? Most manufacturers have a windows based BIOS flash utility that makes BIOS flashing much easier. You can find the BIOS utilities
HERE, and the BIOS files
HERE.
Blue screens are usually caused by driver problems, or memory problems. Have you run memtest + on the machine for at least 4-6 passes? If not, go
HERE, and download the floppy maker for v1.65, or iso for burning a bootable floppy.