Thank you very much for your reply. It really helped. Now my window gadgets are working properly. But, another problem occurred. It say that my Browser Companion Helper has crashed. And also I cannot access my folders Desktop, Download and RecentPlaces (c/o Favorites). It says
This file does not have a program associated with it performing this action. Please install a program or, if one is already installed, create an association in the Default Programs control panel. How do I do these things. Kindly help me.

Thank you.