I don't know a lot, but I know a decent amount, what's the problem?

Okay, so, I had some mods a while back, but then my minecraft began to fuck up. I can't run regular minecraft, it just won't load. I have to download a copy Minecraft(1) and run that copy. I am missing my .jar file also. And when I try to move winrar archives of mods it says that the archive is corrupted. I have tried removing every single minecraft related thing on my computer, and it still does this bs.

Okay, go to where your minecraft 'bin' file is located, and delete that, then run Minecraft, it will generate a new clean one for you.

That didn't help at all because my Minecraft won't run by itself.