Open Activity Monitor located in HD > Applications > Utilities
Type SystemUIServer in the search field top right corner of that window.
Select the process name then click Force Quit.
Restart your Mac.
If that doesn't help, remove all items from System Preferences > Users & Groups > Login Items
Same for HD > Library > StartupItems
Then restart your Mac one more time.
I don't know if this fixed the slow boot, but it made my MacBook ten times faster!!
Can you explain what was the matter and what I did by forcing SystemUIServer to stop? And will this problem occur again in the future and do you maybe know what can cause this problem!
Thanks so far!!