I have a problem that I do not know how to repair.  I am using a ME 8200 Dell.  I was using a downloaded software progran that I had acquired on May 24th and it worked well until recently . What happened was that I cleaned my registry and not knowing what I was getting into or not completely understanding the program I was using.  I must have taken out some thing that one or more of my programs needed.

What happens when I try to start this program my computer tells me that an error has occurrred within the application. (an  exception of class nilobjectexception was not handled) After that I uninstalled the registry cleaner program that I was using I thought that this could possibly be the problem, It was not the problem so I tried to reinstall this program so that I could go back in the archives and retrive what I had removed but I cant reinstall it, My computer tells me that (1607; Unable to install install sheild scripting) I then tried to restore my computer and it says that it can not be restored and that ended my knowledge of how to repair my computer, so if some can help me I would be forever grateful.