Start up problem

[John Wariga]

Hello,
I have problem with my Acer laptop..
It dosent start up normal.when switched on,it starts up with Windows Boot Manager,asking to choose an operating system

 

[dickey005]

Operating system or boot device ?

 

[John Wariga]

Operating system or boot device ?

 

[John Wariga]

operating System

 

[dickey005]

operating System

which operating system r u using ?