Bugs:The Sims 2 (Windows)
This page details bugs of The Sims 2 (Windows).
Custom Food Corrupted IDs
In all versions, Custom Food uses an invalid ID when it is used in cooking contests. The only known way to fix it apart from deleting all custom foods is to use a mod that hides all custom foods in food contests.
Deleting a Sim directly from the family bin can corrupt the neighborhood, due to it not deleting all files related to that family. Deleting a sim directly this way only deletes the main Sim files, and leaves behind any memories, friends, and wants/fears that Sim has and corrupts them. This can also apply if a occupied house is moved directly to the family bin.
Sim on the Phone
When a Sim is on the phone, the game internally considers that Sim to be "Talking" to the other Sim, even though the other Sim cannot be seen. If the game is saved when a Sim is on the phone, the main Sim is reset when the game is restarted, but the Sim on the phone is still considered on the lot and is not reset. This can cause problems with that Sim and other game problems in the future.