Photoshop saves the last 30 files you have opened and displays them in the Recent Files list (File > Open recent), but only the last 10 items will be available! Follow these steps to set the number of items for recently opened files.
To edit the number of items for the recently opened files list:
First, you will have to open the Preferences dialog box: Press CTRL + K (Windows), or Command + K (Mac), or go to Edit > Preferences
Click on "File Handling" on the list on the left
Edit the "Recent File List Contains" field, and select how many recent files you want to be displayed: 30
- Press "OK" to finish