Psp 8gb Card Reader Help?

[catoch]

I jus got a 8gb pro-duo memory stick for my psp with and pro adapter. my psp reconizes all of the memory stick, but when i put the memory stick into the adapter and into my card reader on my laptop it says to formakt the disk. Also i formated it and it only reconized 1/2 of it then my psp only reconized it so i formatted it on my psp and it rconized all of ot agin. the compter managemant says only 1/2 of it is there also. O yeh i have Visa