The Sims 2

There can be various reasons the game is crashing, particularly if it is crashing after just a few minutes. Sometimes it can't be pinned down, but sometimes it's caused by missing or corrupted files or missing or corrupted Sims or lots. If it's any of those things, it can be fixed generally by generating a new Sims 2 file. Or if you know how to use SimPe and batbox, deleting the corrupted Sim or lot. But there can also be issues with your computer itself, like the graphics drivers. 

But if the crashing is intermittent, happens some times and not others, and tends to happen at around 1 hour when it does, then it's likely just the "normal" Sims 2 crash. It's been happening since the game was released. The prevailing theory is that is has something to do with the way the game accesses and uses RAM. Sometimes it simply does it wrong and crashes. 

If this seems to be the case, the best thing to do is save every few minutes, and certainly after anything important. When you get close to 1 hour, close the game. Delete the cache files, then start the game up again. For many of us who have played Sims 2 for the last 22 years, saving obsessively and deleting cache files such a normal part of playing that it carried over into 3 and 4 too.