Dall'help di Windows 7:
How do I add or remove index locations?
The easiest way to add something to the index is to include a folder in a library. When you do that, the content in that folder is automatically indexed. For more information, see Include folders in a library.
You can also add something to the index without using libraries. To add or remove an index location:
-
Click to open Indexing Options.
-
Click Modify.
-
To add or remove a location, select or clear its check box in the Change selected locations list, and then click OK.
If you don't see all locations on your computer in the list, click Show all locations. (If all locations are listed, Show all locations won't be available.) 
If you're prompted for an administrator password or confirmation, type the password or provide confirmation.
If you want to include a folder but not all of its subfolders, click the folder, and then clear the check box next to any subfolder that you don't want to index. These folders will appear in the Exclude column of the Summary of selected locations list.