Exfat win xp 64gb usb memory stick files i copy across go missing?

I have win xp my question is i have a 64gb usb memory stick formated to the exfat iv already downloaded and installed the software from microsoft to allow me to use memory sticks above 32gb the problem i have is when i copy multiple draws across with files in it seems to copy them ok but when i go back to check the draws are still there but the files have gone but if i check with propertys the size is as if the files are still there