Homegroup issues after factory reset

I have a Acer Win 7 laptop and when I bought it nearly a year ago I set up a homegroup on it. Let's call it Homegroup1. I was negligent and did not record the homegroup password, or, if I did, I don't remember where. I had some issues with the laptop and sent it in for warranty work, where they replaced the hard drive and required a factory reset. When I did the factory reset, I set up a 2nd...