Macbook air taking long to boot up (Over 4 minutes) My macbook air start up is acting weird. 


I press start button, 
I hear the apple sound and a blank grey screen appears
Then the apple logo shows on the grey screen with a loading circle below it. 
Then a blue screen appears
and then the grey screen appears with the loading circle (the loading circle doesn't spin though. 
Then the mouse appears on the grey screen
then the blue screen comes up
and then the login box with the desktop image.
A typical issue causing long boot times is a faulty or missing selection of the startup disk. Go to System preferences > Startup Disk and make sure your Startup Volume is selected there.

Another thing which definetly helps to improve startup times on my MBP is running Onyx from time to time and have it rebuilt system caches, etc. (see tab "Automation"). Make sure to backup first.