Try soluto.com to check which is going on with your boot.
Ok, I did.
Complete and clean removal of 4.8. Installed 5.1.889. No malware running (for now-usually run Malawarebytes).
Boot time went from 2:13" > 5:05 (more than doubled---seems even longer)
Avast boot time went from 30 sec. on 4.8 > 51 sec. (is that why it's called 5.1?
)
A BIG chunk of boot was just called [System] and was 81 sec. I did not note that process time during the 4.8 boot so it must not have been significant. Soluto does not define what exactly is the [System(s)] file booting.
In addition a clipboard tool [Clipmate] I use has it's boot process screwed up. This has been predictable in 5.x. It half boots - running in process but not available. I need to kill it with task manager and reload it. It's OK then.
Updates seem normal. Protection seems OK.
Does this help anyone figure out my problem?