Instructions
Check if the memory stick is write-protected. Some memory sticks have write-protection, or a read-only mode, to prevent files from being changed on the drive. Check your memory stick for a tab on the back of it that is in the "Locked" position. If it has this, move the tab to the "Unlocked" position.
Check to see if the memory device is faulty. Connect the memory stick to the computer's USB port and click on the "Computer or My Computer" folder in the desktop start menu. Click on the memory stick's drive icon and verify that you can open the device and read, listen to or view the stored files.
Insert the memory stick into another USB port on the rear of the Xbox 360 console to verify that there isn't a problem with the USB port you are trying to use. If you still can't use your memory stick, then the problem is most likely not the console's ports.
Configure the memory stick for the Xbox 360. Connect the built-in USB plug on the memory stick into one of the Xbox 360 console's rear USB ports. Turn on the Xbox 360 and select "My Xbox," then "System Settings" from the menu. Select "Memory." The connected memory stick will be listed on the "Storage Devices" screen; select it. Choose either "Configure Now" to configure the entire drive, which will erase all of the current content, or "Customize" which will allow you to allocate a certain amount of storage, up to 16GB, for use with the console. If you choose "Configure Now," select "Yes" to erase all data. If you choose "Customize," move the slider over the allocate the amount of space to be used. Then click "Configure."
Update the Xbox 360 console. The console must have the Spring 2010 update or later to work with flash drives. Turn on the Xbox 360, select "My Xbox" and select the Xbox Live tab to sign into Xbox Live. If you don't have an Xbox Live account, follow the prompts on the screen to sign up for one. Click "Yes," if prompted to update your console software. If you aren't prompted, you already have the most updated software on your console.