How do I retrieve the game if I lost it, but I still have the original code that was given to me?
Try downloading the game from its official website, installing it and then using the code that you have to register the application. In case that doesn't work, you can try contacting the developer by sending an email to this address: scott@amuseware.com and asking him for assistance.
Worst-case scenario, if you're still using the same hard disk, you could try installing a file recovery application like Wise Data Recovery or iCare Data Recovery Free to get back the files that you lost.
Scott I am 83 and just received my new PC. My original Yahtzee was lost BUT I signed up for another in the last few days and paid with my Bank of America cc. I have not received any notice or advice from you????/ What now?? I am in withdrawal'''