Watch for Changes: Have Picasa continuously monitor a folder for changes, or look for files in a new location.

If you want Picasa to update to show all the changes made to pictures in a specific folder, set the folder to be watched.

Example: You've been storing all your pictures for years in the location D:\photos. If you want Picasa to notice changes to D:\photos, add this folder as a Watched folder:

1.  Select Tools>Folder Manager

2.  In the Folder List, scroll to the D:\Photos folder

3. Highlight the D:\Photos folder and select "Watch for Changes"

4.  Click OK

5.  Picasa will scan the folders you specified and keep them up to date

All future changes to files in D:\ Photos or its subfolders will automatically appear in Picasa.