My computer does not open flash disk

Hello, please can someone help

when i put a flash disk in, i open my computer, it reads that the flash disk is in, when i click to open the flash disk, it does not open it so i can see the files, it asks me to open the file using, and gives me all the options. but i dont want that, it used to just open it straight away, any suggestions, as to why all of a sudden it would do that and how would i change it back

thanks