here. Have a look to see if your drive is there or not.
Also, check my signature for a link for directions on how to generate and properly post a syscheck. Let's have a look at what's inside your system to see if you missed something when you followed the guide.
EDIT: Oh yeah. SD card. I think some loaders MIGHT be able to be configured to look at SD instead of USB, but it's a bit of a hassle, and unless you have a good quality card, will be slow. You shouuld look into getting a USB drive.
And you should be ripping your games from the disk directly on the storage device to ensure the best quality game rip.