I'm just putting a computer togather now when I turn on the computer after it's done all it's check it'tells me floppy disk fail how can I fix that?

Check the cables.

Go into cmos set up and disable halt on floppy. Or disable floppy drive all together. Also make sure there isn't a disk in the floppy drive and that your cmos is set to boot off the hard drive and not the floppy drive.

Just in case you don't know what cmos is, restart the machine and hit DEL when its checking the ram (in some cases its F2)

Go into bios and disable floppy as your first boot device, set it to cd rom first, hard drive second and floppy 3rd if you can't disable it