UPDATE as of May 2016 Picasa is no longer available to download from Google. It's still out there on the web, still works, and it's still good. But you'll need to Google to find a place to download it. If you're looking for cheap photo editing software, consider Affinity Photo by Serif instead. It's $80, with no rental, and almost as powerful as Adobe Photoshop and Adobe Lightroom.
When installing Picasa, I’d suggest that you DON’T tick the option to use Picasa’s picture viewer, as it changes the way your computer behaves with photos.
When you first run Picasa, it will pop up the following screen:
It’s asking you where it’s allowed to look for pictures to show in Picasa. Don’t worry – it won’t move or copy anything; it’s just finding out where your pictures live.
I suggest that you pick "Only search My Documents, My Pictures and the Desktop" – otherwise Picasa will transform into a bloodhound and sniff out every logo and image stored anywhere on your computer… and show them all mixed-up with your family pictures.
If you want to include photos from other folders, once Picasa is up and running for you, go to the Tools menu, select Folder Manager, select the folders that you want Picasa to include and mark them with the blue circular arrows.
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