Those files get moved to your processed folder and you can import from them again using 'Play Poker -> Get Hands From Disk':
C:\Users\{Windows Login}\AppData\Local\PokerTracker 4\Processed (Windows)
\Users\{Mac Login}\Documents\PokerTracker\Processed (Mac)
Guide: Processed FilesIf you do not see the AppData folder in Windows File Explorer then please refer to
this guide.