After looking through a ga-jillion ROM threads, I have seen these questions repeatedly: "What/where is SPRecovery, I don't have it?" "What/where is Nandroid, I don't have it?" Every thread that has been posted about rooting/ROMS talks about having SPRecovery and a Nandroid backup, but where do we get these? What are they? When I was trying to root, that was the hardest part for me. I was downloading all these files and none of them were labeled as either of these. For the love of god, can someone please explain? From everything I've read, this is what I've come up with At the very beginning when you are actually rooting your phone, every root requires flash_image and recovery-0.99.2b.img,(newest version recovery-0.99.3b.img, but leaving 0.99.2b.img for reference sake)..... So what are those files? flash_image : This is the file that will allow you to write the recovery-0.99.2b.img into the system's files. How exactly it works, I have no clue, and I don't really need to explain much else other than this is the file that lets you get SPRecovery onto your phone. recovery-0.99.2b.img IS ACTUALLY SPRecovery (Thank you SirPsychoS!) SPRecovery is an advanced recovery system that allows you to backup and restore your own files and other ROMs. Okay, once you have gained access rights to your system files and installed SPRecovery (recovery-0.99.2b.img), you have to add a folder that SPRecovery can save to/restore from and that would be: NANDROID! That's right folks, you create the folder yourself and SPRecovery just saves backups to it or restores backups from it. So if you ever need to get back to your lastgoodconfiguration, you can always restore it through SPRecovery from your Nandroid backup(folder). That is if you were smart and actually created a backup file. While you could essentially restore your phone to a full stock from files on the internet, without your own backup, you will lose your data. Full stock means full stock. Note: Some ROM installs have you place the ROM file into the Nandroid folder and run a 'restore' on the ROM to install it to the phone. Nandroid = win. Another thing that I would like to reiterate I have seen answered a few times: Will this overwrite my data? The part about SPRecovery that is really awesome: You get to chose which part of the backup you restore/install. So when a tutorial tells you to uncheck "Data" that means YOU KEEP YOUR DATA. It took me 4 hours to figure this out. Once I realized what these files were and what they did, it took me a total of 10 minutes to actually flash in a custom ROM once I got SPRecovery up and going.