I do this by creating a folder on my Desktop, name it something like "4GBcardbak." Using a Micro SD card reader, With the adapter connected to my PC, I open the drive letter associated with my storage card, then do a "Ctrl+A" to "Select All," and then a "Ctrl+C" to copy. Finally, I open the folder that I created on my desktop and do a "Ctrl+V" to paste.
Since I am going straight from the card to the PC, nothing gets altered in the translation. Card readers are generally cheap these days, usually less than $15 at WallyWorld. Check Amazon too. In fact, check Amazon for the new larger card as well!
Red BB Curve 8330m
v.4.5.138 (Platform 184.108.40.206)