since this is basically an adapter that lets you read/write a micro sd card on your computer...it makes your sd card into a usb thumb drive....size shouldn't be an issue. your computer should be able to read any size card with this. thanks for your interest. in the tiny possibility that your card and computer can't communicate through this reader, mail it back and I will refund your credits. good luck
I don't have a win 8.1 system that I could test it with. it appears that this is just an adapter that lets you connect the micro sd card to a usb port, so it should work in any computer. in the tiny possibility that your card and computer can't communicate through this reader, mail it back and I will refund your credits. good luck