Lets see. 7.3 was released 05/2008.
If you purchased this at the time then the membership expired 05/2009.
Even if you paid for renewal it would not work.
Even if you were able to get a 7.3 version (not available)the file in question would be blank. Because it would be populated by the install script.
It should be your responsibility to make backups including the MySQl database.
The problem is probably your hosting service hosed your file.
With all that said. You can ask your host to restore a older file, should work fine with a few tweaks or Open a support ticket and see if Rick can help you.
Did not want to sound like a jerk but it is the facts.
