Hello, Sathish,     

Your question has already been answered in the other thread you have opened on the same topic. Please, see our answer there for more information.

I will change the status of this duplicated item to declined. Feel free to continue the communication in the following item:  https://feedback.telerik.com/winforms/1398663-hi-please-note-that-i-have-downloaded-and-installed-trial-version-of-telerik-ui-winforms-the-problem-is-when-i-open-child-form-from-parent-form-always-it-takes-minimum-4-seconds-to-load

Thank you for your understanding.

Regards,
Dess | Tech Support Engineer, Sr.
Progress Telerik