Problem opening some application after installing a utility

I have Windows 7 installed on my computer and I was so happy with it, when it worked fine. But recently I am having trouble with it from the day I have installed a utility. I am getting problems like program conflict.
That is whenever, I try to open any application it gives me an error, that the program is already running or the program is not installed properly. I tried to clean up bugs that I thought would have caused the problem but they have not actually done it. Even after running a full scan and clearing the virus I tried opening some programs, which I faced a problem with, but the status is the same.
Anyone faced the same problem? Help me solve this.
