The sims 2 installation serial number

Not legally. The disks need those numbers. Additionally, even if you had them, it's hit or miss whether they work because they can no longer access the Sims 2 site to get the patches that were released. Some people have gotten them to work, but I think it takes a bit of work and different work than it took to get Ultimate Collection working. You'd need to do some googling and digging.

I know people who own the game already don't want to buy it again, I totally get that. I owned the games on disk, then on the EA downloader and Origin, and got Ultimate Collection when they released that. It felt weird to buy the game again. But, when I thought about all the effort I had to put in to keep the game running (altering files, editing settings manually, installing mods, trouble shooting every time I got a new computer) I decided it would be worth it to have a supported game again. It had been 21 years since I actually bought the base game, and it was originally $50, plus whatever I ultimately paid for in packs. Legacy, with everything except IKEA was only $30. And I was able to put IKEA back in myself.

Some people are still having issues after the updates they released, but my game runs beautifully with no problems. If you have the money to spend and really think you'll play it, I say buy it. If you aren't sure, check out videos on Youtube and see what other players think first.