|USB flash drives have a limited lifespan, especially if they get bad treatment. Windows will refuse to recognise it after a while and the only thing you can do is throw it away and buy a new one.|
Cheaper ones with obscure brand names (Color Turn? I've never heard of it) are not worth buying. Spend a bit more on a well-known brand like Transcend, Sandisk, Kingston or Verbatim. They are more robust and less likely to give trouble.
But whatever brand you buy, you should never use one for storing important files!
They are designed only for short-term storage such as when you want to transfer a few files from one PC to another.
They are too unreliable to use as backup media.