Can't open my USB device

Hello,

I need help with my USB device..
I have a 4 GB pqi(brand) USB and i'm using it for more than a year now..
My problem is when I plug it into the USB port, I cannot open it.. even though the window explorer for computer(My Computer) is open, and that it is shown as removable disk(g:)
I still cannot access my files .. when I click to open it.. a message appears saying: Please insert a disk into the drive.. furthermore, in the properties of my USB device.. it shows 0 bytes for both used space and free space.. I don't know what is the problem.. I don't even know if the problem is in the hard drive or the device itself..

I have also read other posts in this forum related to my problem.. but I didn't try any of the solutions that have been suggested.. because i'm having a hard time following those steps because i'm not familiar with BIOS file and command prompt, and data recovery softwares..
I'm afraid that if I try to do those things, I might lose a large no. of files on my PC.
I'm just hoping that there is/are another solution(s) I can try that is easier..

PLEASE, ANYONE HELP ME?! LEND ME YOUR HELPING HANDS, ANYONE!?
ANY ADVICE/SUGGESTIONS/TIPS WOULD BE GREATLY APPRECIATED..
THANKS!!