1. Organizing and viewing in folders

The obvious way to organize photos is by folder. If you put all of the pictures from your Hawaii vacation into a “Hawaii Vacation” folder, you’ll know where they are.
But that’s limiting. If you want to find the best photos of your daughter, you’ll have to open an awful lot of folders. Or find a better way.

You can view all of your photos without worrying about folders. Open your Pictures library in File Explorer (Windows Explorer in Windows 7 and earlier versions), click the Search field in the top-right corner and type *.jpg.
Once the files are all there, right-click a blank space in the file view and select View > Extra large icons.
Of course, you’ll still have a ridiculously large number of photos to go through. If you remember—even approximately—when the photo you want was taken, that can help. You can group by date, sort by date, or even search by date.

2. Tagging photos

Tagging photos provides much better search capabilities. If you’re looking for pictures of Mary and Jose, you can search for tag: mary jose. But that only works if you’ve set things up ahead of time.
Every .jpg file has an editable tag field in its metadata, and you can enter multiple tags in each. Select a photo—or a group of photos—to which you want to assign a tag or tags (separated by semi-colons). You’ll find the editable Tags field in the Details pane. If you’re using Windows Explorer (Windows 7 or earlier), you’ll probably find that pane at the bottom of the window.
If you don’t see the pane, select Organize > Layout > Details pane.
f you’re using File Explorer (Windows 8.1 and 10), you probably won’t see the pane until you turn it on. Click the unlabeled Details pane icon in the View ribbon’s Pane section. It’s the lower of the two small icons next to the big Navigation pane icon. Once visible, the Details pane is unmissable on the right.

3. Picasa 3 photo organizer offers new ways to search

But if you really want to get serious about this stuff, I recommend you download Google’s free photo organizer, Picasa 3. Among its other tricks, it can recognize human faces and can usually guess who is who (after it gets to know the people you often photograph). It also has a timeline of photos and can even display a map that shows where a photo was taken.
Google also has a cloud-based photo organizer called Google Photos, but it’s not as powerful as Picasa. For instance, it can recognize faces very well, but it doesn’t support jpg tags. Also, it’s part of Google Drive, which means that once you pass 15GB, you have to pay.