Plug In Editor Problems

I installed a bunch of plug-ins. One of them was Role Manager I did not notice that there was problem with this version of role manager with 2.1. At one point, I could not longer add plug-in. I would activate them and I would get IE comment that page can not be seen.

I read that role manager may be a problem so I went to look at my set-up and accidently deleted adminster’s role to activate. I did not know how to get that function back. I went and deleted role manager from my files and then I lost the plug in editor page completely. All I have is a subpanel of Plug in Editor (which I never had before). I do not understand PHP but if someone can walk me through I can do it.

I uploaded new role manager thinking that would fix everything but I can not activate it. Help.