^ You may recover your files on 2 conditions
1. You performed a quick format
2. After quick format or deletion you didn't use the file space that was deleted.
When you delete a file, a '?' is placed in the first letter of the file in the FAT (File Allocation Table), it does not actually deletes the file from hard disk (ever wondered why deleted is so fast ) so it does not show in explorer. To delete a file completely we use shredders.
Similar thing happens when you perform a quick format, which gives a new FAT to the drive but the files are still there in the drive i.e. they are not deleted.
If you have performed the above two operations and didnt copied or moved or defragment your drive, there is a good chance your data can be recovered.