For KeePass the password file is "Passwords.kdbx". If KeePass will run, once it's open go to File > Open > Open File. Or click the "Open" icon on the menu bar. You should then be able to open your password file.
I'm using what's called the "portable" version of KeePass Pro. This version does not require an install. You just unzip it to a directory of your choice and run it.
You can download the latest version here:
http://keepass.info/download.html