There are lots of freeware application including Microsoft Pro Photos tools to edit meta information of photos. You can also add or edit tags, author details, rating, title and subject in Vista easily and quickly. This can be done for a single photo or multiple photos. To add the photo details select a photo and you can see the details at the bottom of the explorer window.
You can add details against Tags, Title, Comments, Author and also Subject. Once you add/edit the details, you can save the details by clicking the save button.
This can be done for multiple photos as well, all you need is to select all the photo and click the Show more details link and do the same process.
Now all your photos will have the same details.