Following are the steps to add gadgets in windows vista:
1. Go to start button.
2. Click on all programs.
3. Navigate to the accessories folder and click on it.
4. There you will find the windows sidebar menu, click on it
5. As you click on it, the windows sidebar will display, it will show three gadgets including a clock, feed reader and image slideshow.
6. Windows vista has default configuration to display the sidebar at the right side of the screen and show only one sidebar.
8. A wizard will open which allows you to configure the sidebar according to your wish like changing its alignment, number of sidebar on screen, etc.
9. To change the default gadgets or to add gadgets in windows vista, right click on the sidebar.
10. A pop menu will display, click on add gadgets option.
11. A wizard will open showing all the downloaded gadgets; from here you can select and install gadgets.
12. You can download gadgets, by clicking on the get more gadgets online, found at the bottom of the add gadget wizard.
13. You can also remove any gadget from the sidebar by simply clicking on the close icon, showing at the right side top.
I believe the steps to add gadgets in windows vista mentioned in this post which I have shared will be easy to understand and would help you.