Gigabyte 990FX UD3 stuck on loading operating system

[Ramtruck]

I have a Gigabyte 990FX UD3 mobo and I have my windows 7 OS on a flash drive. After getting my computer to turn on and everything for the first time,
I have my flash drive in the port, but I get stuck on a screen saying "Loading operating system... Boot from CD/DVD:"

I know that there are posts about this problem all over, except I can't find a straight answer. I'm only 15 and don't really 100% understand all of it, so step-by-step instructions would be great, and just ask what you need.

[Vezina]

... I have my windows 7 OS on a flash drive ...

First, to boot from a USB stick you need to make sure you can select it to boot from.
Press F12 to invoke BOOT menu or restart (Alt+Ctrl+Del) ,after you ve inserted the USB stick, to make sure it appears in the BIOS boot menu order.
The same you do when you update BIOS, the  USB stick must be inserted and one restart made before you can proceed.

You should also make sure the stick is inserted in the USB 2.0 ports as the USB 3.0 ports supplied by 3-rd party chips will not work until drivers are loaded(opposed to the FM2 platform where USB 3.0 is natively supported by the AMD chipset)

Then you are not saying if you have it on the stick as installation media(DVD replacement) or as a portable OS.
W7 does not work as a portable OS and if it does it s not what Microsoft intended to and the probability to work is unknown.

You should specify the full hardware configuration nevertheless.

[Ramtruck]

Thanks for all the information! Here's my build:
NZXT Phantom PHAN-001WT Case
KINGWIN ABT-750MM 750W Power Supply
GIGABYTE GA-990FXA-UD3 AM3+ MOBO
SAMSUNG 840 Series 2.5" 250GB SATA III Internal Solid State Drive
Seagate Momentus XT 500GB 7200 RPM Solid State Hybrid Drive
FX-8150 Zambezi Processor
GeForce GTX 550 Ti Video Card
Kingston HyperX 8GB 240-Pin DDR3 RAM

And when all of my files are on my flash drive, it calls it a "USB Disk"

[Ramtruck]

IT'S WORKING

[Vezina]

It s good that it works ,even though you still haven t enlightened me of what are you doing with the USB Disk 
I wish you a happy usage.

[Ramtruck]

I guess I should let you know what went up!

I figured it couldn't be a hardware problem, so I checked it out online and I had to prep my flash drive for windows 7 install.