Recently me and my wife enjoyed playing this game. It so happen that we need to re-format the computer and need to backup our saved games. I looked everywhere on the net but can’t seem to find the location of the saved game file. I was using windows 7 at the time. I tried copying the whole Plants vs Zombies folder as they said, the game files are hidden.
Most on the net pointed to:
C:\Program Files\Popcap Games\Plants vs Zombies\UserData
This does not work for us.
On windows 7 this location worked for us:
Copy the whole userdata folder including the user*.dat and game*.dat files.
Hope this helps someone.