Hello,
I plug my 4G Lexar memory stick in, it always worked before but now when I plug it in it is said that either it can't detect it or something is wrong, unable to register. HELP???!!!!
Probably time for a new USB drive. They can and do break/wear out and I never recommend their use for critical stuff (without a backup elsewhere. Try another USB port. If that fails, then it is time for a new one.