I have installed Ubuntu 16.04 alongside Windows 10. After the installation process finished, I clicked on restart, but still Windows is booting. There is no boot selection menu. Is there any key to press or anything else I can do? (I am using an Acer laptop.)
You have to disable Fast startup and hibernation in Windows 10, otherwise Windows will always boot when you switch on your machine. Boot into Windows, open Command prompt as administrator and execute :
powercfg /h off. Open Windows Control Panel, go to the Power Settings and uncheck Fast startup. In case this option is not visible, enable Show hidden settings. Shutdown the computer completely - do NOT reboot. Boot into BIOS and select Ubuntu as default operating system to boot.
If your bios is UEFI, then you should be able to press the key at boot (it depends by manufacturer, F2, F4, F12...) and instruct your PC to boot on Ubuntu.