Memory cards are a type of portable memory storage than many different devices, such as MP3 players and digital cameras/camcorders, use to store digital files. These cards can be easily replaced or upgraded. In some cases, a memory card will need to be formatted, sometimes to fix an error on the card. Because formatting involves wiping all the files off of it (that are not hardwired into the card), this can result in the loss of some files. But you can still format a memory card without losing the files.
Connect your memory card to your computer. In general, memory cards will communicate with a computer via a USB port. In some cases, the memory card will need to be inserted into the camera or other device, which can then be plugged into the computer.
Access the files. You can do this by opening "My Computer" and looking for a portable storage device. These devices may have a letter drive associated with them (as in, E: drive) or may simply be listed at the bottom of the screen as a removable memory device. Regardless, open the drive or device and locate the files you wish to keep.
Copy the files. Highlight all of the files you wish to keep (hold down the "CTRL" button to highlight multiple files). Then hit CTRL+C to copy the files. Transfer them to a folder on your computer by creating a new folder (or using an existing one) and then hitting CTRL+V.
Format the memory card. Do this by right-clicking on the drive (or device) that appears on the "My Computer" screen, and then select "Format" from the menu that appears.
Replace the files on your formatted drive. Copy the files from the folder you created/used, open up the memory card (from "My Computer") and then hit CTRL+V again to paste.