Do you ever wonder what this message really means? Is it really important?
The Answer is Yes.
Similar to the computer taking time to start up, the computer also takes time to shut down. Some updates require installation during the shutdown process of your computer which can cause the computer take even longer to shutdown.
If you see a notification window similar to the image above, be sure to not force your computer to turn off by unplugging the power cord while it is updating. Your Windows operating system is built with important registry files. If these registry files are corrupted (mixed up), your computer will not run properly, maybe not even at all. This also applies to you Apple users, too. Your OS X operating system also suffers if you don't allow software updates to install properly.
Tip: If you are trying to install software updates on a laptop, be sure to plug in the power cord before you begin. This will ensure the computer will not shut down unexpectedly due to a drained battery. Some laptops will prevent the update from starting if a power cord is not plugged in.