Sims 2 Nightlife - Please Insert Disk 1

I have The Sims 2 and several expansions and stuff packs installed. When I tried to download Nightlife, as soon as I enter the disk into the computer, it immediately gives me a pop-up message saying "Please Insert Disk 1". That's the disk that I put in. All the other games installed with no issues. I tried contacting EA and they said they don't have much help because The Sims 2 isn't really supported anymore due to age. I read on the forum that you can redeem your product code through Origin and download it directly from there, but it said the code is invalid. I contacted EA again and they said they don't carry The Sims 2 on Origin. I'm really confused and would like to know if there is any way I can resolve this, or if I will have to purchase a whole new game. I am running it on a Windows XP if that makes a difference (I know, it's old but that's what I have at the moment). Thanks!