Just got my S3 today through Verizon. Got my 8 gb card out of my old LG Vertex, had all the apps on it, plugged it into my S 3, nothing showed up. Playing music and viewing my gallery shows my pictures and music, but using es file explorer shows no trace of my sd card. I don't want too just format the card, since I have music and pictures I want to keep. The version if android I was running on my old phone was 2.2.2 would that cause any compatability issues? Any help on how to use my sd card without formatting would be greatly appreciated
While reformatting the card is always a good idea when changing phones, since your phone is reading your media files on the card, you don't absolutely have to format it. You can get by without doing it.
There are two things going on here. The first is that ES File Explorer doesn't navigate to the root directory of the phone by default. This is a problem because the OS handles the actual SD card in a way that you're not used to coming from 2.2.2. The S3 reads the internal memory as the SD card and reads the actual SD card as an extension storage area. ES File Explorer does not take this into account, so it's reading the internal memory as though it's the removable SD card.
Here's what you need to do in order to see your microSD card in ES. Open ES File Explorer, tap menu, and then settings. In the settings, scroll down to the option that says "Up to Root" and select it. Next, tap the back button to go back to the folders in your internal memory. From there, tap the "Up" button at the top of the screen. Now, open the folder named "mnt." Your microSD card is the folder named "extSdCard." Open that up, and you'll have access to all of your files.
ES File Explorer makes things much harder than they need to be in order to get to the external microSD card in the S3. I would recommend using either
Astro or the stock My Files app for file browsing. My Files is the most straightforward way to access the microSD card, but it's also limited in features. Astro has many more features, and can be set to automatically open directly to your microSD card (exSdCard).
You also said that you "had all the apps on it." The S3 doesn't support moving apps to the SD card, so your apps won't be able to use the app data that's on the microSD card. With some apps, you can copy the data over to your internal storage, and it will work. But I wouldn't count on that working with too many apps.