1)Go to start- Device manager, right click on Disk drives and click on Scan for Hardware changes.Also there is a Universal Serial Bus Controller, do the same thing. Do you have another Flash drive? If so, plug into computer with Norton 360 installed, and see whether it will open any other flashdrive. If you don't have another one, just buy, even the cheap one, and store some files from your flashdrive, if it does open any other flashdrive, then it means that that one that deosn't opne, has some file that Norton blocks or that Flash drive is somehow problematic.
2) Use malwarebytes.org their software to detect , maybe a virus to scan your PC, download, install/update with the latest updates, and do a QUICK SCAN., not just your USB , but entire drive C.IInstall malware bytes on your laptop, plug your Flash drive, and let malwarebytes scan your USB drive and entir e C, it might find something. You can also do a Full system scan.
3). maybe restoring your PC to a previous state when usb Flash drive worked fine , would do the trick.Probably after that you will need to reinstall your Norton. Make sure that you already have a Restore point or create a new one, if you want to go back to your PC state as it is now
4) is your PC is out of warranty? If not, then contact manufacturer. They can acces remotely your PC, and see what the problem is. If it out of warranty, than you will have to pay for technical support, I think.
5) finally, go to
http://us.norton.com/support/contact/contact.jsp?pvid=cs
Tell them what the problem is, request supervisor if it needed. You will have to give them permission to access your PC remotely. I hope they can fix the problem. If not, then they MUST replace your PC with some other Norton compatible software.
Let me know , how it's going.