There are two ways to copy files onto the SD card:

 1) Use a USB cable to connect your Android to your computer. When the USB cable is connected pull down the notification bar displayed at the top of the Android screen and then select the “USB connected” entry on the list which will allow you to mount the SD card to your computer so you can copy files to and from the SD card and the computer. When you are finished you will have to pull down the notification bar again and select the “Turn off USB storage” entry which will dismount the SD card from your computer and then mount it so that the Android can access it again.

 2) Physically remove the micro SD card from your phone and plug it onto a slot on your computer. Since micro SD cards are so small you usually need to have a micro SD to regular SD converter in order to plug it into your computer. This also requires that your computer have a slot where you can plug in SD cards. Most computers now do have these slots since SD cards are used in all types of electronics devices including cameras, and many people plug the SD cards from their cameras into their computer to transfer the pictures. You may have a compatibility issue if you buy an SD card that is 4GB or larger and your computer has an older SD card reader. SD cards that are 4 GB or larger are called SD-HC cards (the HC stands for high capacity) and older SD card readers will not be able to read these high capacity cards.

 Using the USB cable is usually the simpler way to transfer your files.