Yeah, i was about to switch out my minecraft folders (one for pixlemon, one for regular survival). After pressing %appdata% i clicked and started to drag the pixlemon .minecraft folder. Accidentally, i let go of clicking while it was over Book Place. It then insta disapeared. It's not in recycle bin, its not in any of Book Place's folders, its just gone. After running minecraft, it reset and remade a .minecraft folder, but all my worlds and days of work are gone. Is there a way to load a prievious version of my comp that will affect app data. I use a windows 7. I hear doing a total system restore works but the stupid thing's nearest restore point is too far.
You can try a data restoration program either specifically for your app data or recycling bin.
Here's a topic on some programs you can use: http://pcsupport.about.com/od/filerecovery/tp/free-file-recovery-programs.htm