The first step is to stop taking photos. The more you use your memory card, the more photos you can lose. Next, remove your memory card from your camera, place it in a protective SD card case if you have one, and keep it in a safe place until you're ready for recovery.
The simplest way to recover your photos is to use one of the many photo recovery programs available. Some cameras come with photo recovery software. If you have this software, use it. If you don't have software already, you can do a quick online search for recovering photos from a memory card. You'll find lots of advice and many programs to choose from. There is plenty of freeware available to recover photos from a formatted memory card. However, if your data is truly valuable, you might want to try a higher end commercial product.
Once your file recovery software has finished downloading, you can get down to finding your digital photos - a simple process now that you're armed with software.
Insert your memory card into the SD card reader on your computer or an external SD card reader connected via USB.
Run your software and follow the step-by-step instructions. If all goes well, your photos will be recovered!
Once you've found your photos, save your photos to a new disk. Remember, saving your recovered photos to the same disk may overwrite other photos you are also trying to recover.
But what if you didn't find your files?
A formatted memory card isn't a problem you can fix by throwing money at it. But if you simply feel like you are in over your head, hiring a data recovery professional may be worthwhile. Before you do, you should evaluate whether or not they'll be able to recover it at all. Some photos and videos may be simply irrecoverable.
If you have any of the following situations, a data recovery pro may not be able to help you:
All of the above situations could mean that you are simply out of luck. If you do want to consult a data recovery service, ask what they charge for a diagnosis or evaluation. Best Buy, Walgreens, Staples and other camera shops and "big box" electronic stores offer data recovery. But it can be pricey.
The only time I would advise you to go straight to a data recovery professional is if you have absolutely no idea what you are doing. If you've read all my advice and understood almost none of it, then avoid attempting a photo recovery on your own - you may make the problem worse. ASDFyou format your hard drive, you create a new file system for your data. This means that meta data for all your files before formatting have been deleted. Most or all of your files are still on the disk at this point, but the record of their location has been deleted. Data recovery software can help you find the data without the location records. However, the more you use your computer, the more data you overwrite, thus the greater chances of your data becoming unrecoverable.