My flash drive won't work.

I’ve been on the forums for a couple hours now, but had to register to get further help. Through all the suggestion on how to fix my cruzer pop none have worked and this has left me frustrated. I’ve done all methods at least 3 times, which include going to device manager and uninstalling both the disk drives and universal serial bus controllers, where my USB is found and uninstalling that, then reinstalling both. Nothing seems to work. When on my laptop my USB comes up as unknown device, and fails to be recognized. Up until a couple days ago it was working fine, now its not working. Please help me fix it, I’m a student and I have important work on it that has to be handed in, in a couple days.

Thanks alot