I was trying to make my own resource pack, and I put lots of unneeded files in it, such as my bin folder. I deleted it thinking it was a bunch of copies, but turns out, they weren't. I tried to get it back but I couldn't.
How can I recover these files?
If you download the newest launcher you can just pick which version of minecraft you want. So, it's no big deal, just choose the version you want, and it will download upon launching.
However, if it was a special jar with mods added to it, like Young Guilo said, check your Recycling Bin. If its not there your gonna have to install those mods into the jar again.
If you accidentally delete some files, you can try to use some file recovery program to recover these files.
One of the most famous file recovery tools is r-studio or r-undelete, which can you can download a trial version here(http://www.r-studio.com/ ). However, it's quite expensive.
A free tool available is Recuva (http://www.piriform.com/recuva). this is quite promising as it is produced by the company that create the CCleaner. I have recovered some file successfully with this tool.
A Tip: If you accidently delete a file, you should stop writing any file into that hard disk to prevent damage to your deleted file.
