RoboHelp application not opening

I am running RoboHelp Office X5 on win XP. I have been using the application for at least a year and a half. I recently upgraded my machine and was able to run the application and have made several updates. Today for some reason, I cannot get the application to run. When I click on the application icon, I get an hour glass for about 3 seconds. It then goes away and the application will not start. The only changes I can think of that have been made on my machine recently is I have upgraded to the most recent version of Rational Clear Case version software and I have also upgraded to IE 7. Other than that I have not made any changes in the software on my machine. We have purchased RoboHelp 7, but it will not arrive for a several weeks and I need to make updates immediately. Any help is appreciated. Thanks