The wallet file is not empty and you still have the blockchain_headers and config files. Delete blockchain_headers and config files and run electrum. If it still doesn't start up then open up the default_wallet file in notepad and see if you can see the seed that dabura667 was talking about before. Notepad is a text editor while wordpad is a word processor. I think you'll have better luck with notepad.
I wasn't clear, I deleted those files and tried to run electrum. It didn't work then I moved them back to try something else. I've opened the deafault_wallet with Notepad (not wordpad) as suggested twice now and it comes up empty.
According to the screenshot you posted the default_wallet file is over 100KB in size. So how can it be empty?