Forget what Software Updates you’ve installed? You can easily check inOS X:
- Open “System Preferences” from the menu
- Click on “Software Update” and then choose the “Installed Software” tab
From here you’ll see the precise installed date and time, the software update package name, and the version of each update listed.
This list can be helpful to look through for troubleshooting purposes, or if you’ve ignored some updates and plan to install them manually through the command line or by downloading the packages from Apple.