Yes, members, posts, topics, forums, permissions etc.. are stored in the database. You could almost state that the database IS the forum. The files themselves are tools to get the info from the database and to present that data in a readable form.
Reinstalling implies starting from a empty database which, during the install process, is filled with some essential data (ex. the admin account).
But let's get something clear along the way. Your forum has 1post in (probably) 1 topic, even though the statistics incorrectly show 3 posts and 3 topics. There is at least 1 member (the owner of that 1 post, perhaps the admin). If there are more members there will be few and you could either let them reregister (on a newly installed board) or install them yourself manually (keep the data from the users_table).
So, why spend more time waiting for a solution to a problem whch cannot even be investigated with the info provided?
Just take a backup of the tables which have information which you could restore to your new forum if needed (very doubtful with only 1 post really). Install a new board and if the problem persists ... use the Support Request Template because currently this is leading to nothing.