Thank you for all the help. Still that did not solve the problem.
Finally, I figured out that it was my C Drive which was causing the problem.
When I installed the Videopad on my D Drive then it solved the problem. Now the program runs with simple double click.
Now I have to figure out why it did not work on C Drive, while all other programs are working fine on C Drive. Why only videopad is not working there. Hope i will figure it out also soon.
Thanks anyway for the quick and prompt help provided by you.