hi

best advice would be to reformat the drive see my pic and use the settings as i have shown then i would check disk as in pic then assign readyboost

and see if this helps.
format
1
Start your computer and plug in the flash drive in the USB port.
2
Click on "Computer in the start menu. and locate the drive"
3
right click on the drive and click format and choose your settings
check disk for errors
1
right click on the drive
2
click properties
3
click tools
4
in error checking click "check now box"