.exe files and apps don’t want to install anymore.

My Dell Inspiron suddenly stops on functioning some months ago after I performed a full restore. When I say full restore, I re-installed the entire programs and everything. I managed to make it work, only that I have some issues as expected. When clicking on the install program, it doesn't show anything nor run the installation. I tried to install Google Chrome but it won't allow me. Even if I run it under the Administrator mode. Nothing really works. What could be the problem and the possible fix for this?
