When asking someone to troubleshoot, it is always neccessary to state fully what the error message says. Most of the time, the error messages occur because you changed something in your system. (I.E. added another program that may have changed a file, went from shareware version to registered version. etc..) It's important to state what you did prior to the problem occuring. You may not recall details but they are most important. When something is ruined in my system, I sometimes have to completely reinstalled my entire operating system, and carefully check my system after each change to find what caused the problem. This includes every change. (I.E. Windows Updates, done one at a time, Program additions, driver additions). Clearly, if it was working before, you changed something.