Uninstalled then re-installed Java and now Minecraft and my Minecraft server will not work?

I had been having issues trying to log in to Minecraft so I uninstalled then re-installed Java to see if that would fix my problem (that had worked for me before.) But after I did that, when I would click on it to launcher an error would come up saying "requires Java Runtime Enviornment 1.6.0". So I tried installing a different version of Java (Java SE Runtime Environment 6) and that allowed to open the launcher, but I still can't log in, and now I can't run my Minecraft server either. Does anyone have any idea of what the problem is. I have tried installing the newest version of Java as-well as the 64-bit version as-well as multiple older versions of Java and none of those worked, and yes I didn't uninstall each version of Java before I tried a different one.