One thing I do is to not connect to the Internet until the system is fully up and running. This avoids all issues you are seeing.

If wired, connect only once the last taskbar icon comes into place, and set wireless to connect only on demand. Boot time to usable desktop on this old W7 machine is about 45 seconds with the current setup and running an old SATA II drive. Still as fast on boot as the day it was first started. (Actually it is faster, since the first boot ever was without an a/v solution installed.)

(Note: No registry cleaning has ever been done on this system.)