I do not remember the details but I got some Bitcoins for free years ago. I think it was on a slot but can not be sure. How can I go about trying to find out where I would have put them if I even kept them at all. I might even have lost them right back to the slot if that is where I got them. I just remember getting them at a time I never had heard of them. Just a thought. why not find them if I can.
If you withdrew the BTC then you must have had a wallet somewhere to withdraw to. A wallet software could have been installed on your PC or, could be with a web wallet provider or, the balance could still be with your slots.
If you have no information about your wallet (check old emails for account information from a web wallet provider), cannot remember any details and, cannot find any evidence of any Bitcoin wallet on your PC (there are may but, they all make a data folder somewhere..) then, unfortunately, your BTC is lost.