Hide and unhide hidden photos and folders; reset password
Folders and and photos in Picasa can be hidden
Folders:
Right-click a folder and choose "Hide Folder"
Note: Hidden Folders can only be viewed in Flat Folder View (under the View menu)
Hidden Folders can be password protected by right-clicking on the Hidden Folders category then choose "Add/Change a password..."
"Add Password" box opens. Either click Add Password or Don't Add Password
If adding a password, "Please enter a password to use for this collection" click OK
"Please verify your password" by typing it again, then click OK
Photos:
Right-click a photo and choose "Hide"
Unhide hidden photos in Picasa
Right-click the photo and click "Unhide"
Unhide hidden folders in Picasa
In Picasa switch to Flat Folder View: Go to the View menu > Folder View and select Flat Folder View
In Flat Folder View (left column), scroll down below the end of the Folders collection
Look for a category called "Hidden Folders" then right-click on each hidden folder and select "Unhide folder"
If the Hidden Folder(s) are password protected:
Click the red > icon in front of "Hidden Folders"
"Password Entry" box will open.
Type the password
If you forgot the password, see next tip to reset a password.
How to reset a password on a hidden folder in Picasa
If you don't know the password, reset it as follows:
Exit Picasa
Confirm that you can view hidden files and folders in the Windows Explorer view menu.
Navigate to C:\Users\<YourUserName>\AppData\Local\Google\Picasa2\db3
Find then delete the catdata_info.pmp file in the db3 folder
Restart Picasa
Find the Hidden Folder category using Flat Folder View (under the View menu) and you can now unhide the folder if desired by right-clicking and selecting "Unhide folder"