Windows Vista has a new built-in searching engine that is completely integrated into the operating system, but not all files are indexed. To add a new file type to be indexed, you just have to follow a couple of steps.
To get to the indexing service panel, just type index into the start menu search box, and hit enter.
In the Indexing Options window, click the Advanced button:
Now, type in the new extension and click “Add new extension”
If you want the file contents to be indexed as well, find the file type in the list and make sure you select the “Index Properties and File Contents” radio button.