Q:

Avoid restarting PC after S/w update

I learned from this question why, but is there a way to identify which services need to be restarted so that a PC reboot can be avoided? 

A:

Rebooting to solve a problem is not the same thing as rebooting to complete the installation of a software update.   Typically a reboot is required after installing a software update because at least one of the files to be updated was in use; rebooting allows the file to be replaced before it is used again.   But to answer your question (sort of): try WhyReboot.