Switch zorin / win

hy, sorry my bad english. I have installed zorin core 18 now on pc with win 10. the installation go good. I choose both wind and zorin and I want to choose what to use every time I start pc. but when I start pc start only win with no possibilities to choose. during installation zorin said that it was possible. if I go back in installation program I said zorin installation in ext 4 but I am not able to understand how to start it and to choose win or zorin when pc start.
hope I explain the problem. thanks for every help. regards

What computer model do you have?
Do you see an ubuntu entry in your BIOS at boot options and can you set ubuntu at first position of your boot order to boot Zorin?

I have an hp notebook. it is no ubuntu in Bios.

Did you disable fast boot in the BIOSvand did you also changed hidden Power options to prevent hard drive going to sleep? These options mean that Windows will always boot first.

How did You installed Windows? You should have seen in the Installer 3 Options:

  • Install Zorin alongside Windows
  • Erase Disk
  • Something else